— Photo by Mike Nardacci

The famous Knife Edge on Maine’s Mount Katahdin was formed when glaciers on opposite sides of the mountain slope carved it into a narrow, perilous ridge.

The goal of every serious mountain climber in the Northeast is to bag the three Big Ones: New York State’s Mount Marcy at 5,344 feet; Maine’s Mount Katahdin with its famous — or infamous —“Knife Edge” at 5,267 feet, and New Hampshire’s magisterial Mount Washington at 6,288 feet with its notoriously changeable weather that has killed more climbers than the other two peaks combined.

Since not one of these is much more than one mile above sea level, in-shape climbers are not likely to be much affected by the drop in air pressure on any of them. However — especially on the summit of Mount Washington — many climbers who carry sealed bags of chips or trail mix will notice that the bags have puffed up and appear ready to explode as air pressure drops noticeably even over that relatively small elevation change.

Mountains generally form through one of two processes: volcanic eruptions and tectonic plate collisions.  Many great mountains in the contiguous United States such as mounts Rainier and Hood and Mount St. Helens are active volcanoes formed largely of the light-colored igneous rocks rhyolite and andesite and dark rocks called basalt and gabbro, and are high enough to have glaciers spilling down them.

When they erupt ,as in the devastating Mount St. Helens event in 1980, the glaciers instantly melt and produce catastrophic blasts of boulders, pulverized rock, and searing poison gasses known as pyroclastic flows, which devastate the landscape and bury everything around them in a slurry of hot mud and ash.

On the other hand, many of the high peaks in the Northeast such as Katahdin, Washington, and the other White Mountains, rose millions of years ago when the tectonic plate that would become Africa and Western Europe collided with the plate that would become North America in the event known as the Acadian Orogeny (“orogeny” means a mountain-building episode). The plates were like two 18-wheelers crashing into each other nose-to-nose, crushing and distorting the cabs, trailers, and their freight. 

Mountains such as these — once of lofty Himalayan grandeur but torn down by erosion — tend to be composed of igneous rock such as granite and metamorphic rocks such as gneiss and schist. The origin of the Adirondacks — which continue to rise — and the West’s Rocky Mountains, all of them far from tectonic plate boundaries, are geologic mysteries over which geologists contend in sometimes heated debates.

One recent theory holds that far beneath the Adirondacks lies a crustal “hot spot” similar to the one beneath Iceland that millions of years hence may erupt in a series of volcanoes.

In any case, Mount St. Helens tops out at over 10,000 feet along with others in the Cascades and the Rockies, many of which rise to over 14,000 feet. They are not only high enough to have year-round snowfields and glaciers but extend into the upper reaches of the layer of the atmosphere in which we live called the troposphere.

Half of our atmosphere’s weight is packed into the lowest 3 ½ miles; even at 10,000 feet — less than two miles, far higher than any of our eastern peaks — most people will begin to find breathing labored and even the most fit climbers will note the increased effort in ascending, especially with packs.

 

Attempting Rainier

Some years back, having climbed Washington, Katahdin, and Marcy along with 38 other of New York’s fabled “Forty-Six” peaks over 4,000 feet, I proposed to a friend that we fly to Seattle and join an expedition with a company called “Rainier Mountaineering” to the top of Mount Rainier.

The company offered two-day treks to the mountain’s glacier-encased summit led by highly experienced guides, some of whom had climbed in the Himalayas. We prepared for it as we would for any Eastern peak — running a few miles on alternate days and doing limbering exercises.

But, when we met our companions the day before the start of the expedition, we got a rude awakening. Many of them had spent the previous two weeks in Colorado or California climbing mountains of equal height to Rainier but without the glaciers — and they had carried 40-pound packs.

It turned out that our lead guide was going to be celebrity climber Ed Viesturs, who had just returned from his fifth ascent of Mount Everest — and he had done it without oxygen tanks.

My friend and I gave each other looks that said, “We are seriously in over our heads.” We learned later from his autobiographical book, “No Shortcuts to the Top,” that Viesturs has a lung capacity almost 50 percent greater than that of the average male.

Day One of the trek began at 10 in the morning at the venerable Paradise Lodge at an elevation of 6,000 feet on Rainier. Though the date was July 6, there was close to five feet of tightly-packed snow on the ground, melting rapidly into rushing rivulets and rills beneath the high summer sun.

With 10 companions and the energetic Mr. Viesturs in the lead, we began our ascent of the steep snowfields up a series of switchbacks following red flags on stakes that led to Rainer’s summit.

It was a stunningly beautiful climb. The trail at first wove its way through groves of  pines, gradually decreasing in size with altitude but it soon led us above timber line with spectacular views of the gleaming blue and silver glaciers plunging down from Rainier’s summit.

To the south loomed some of the great volcanic peaks of the Cascades — mounts Jefferson and St. Helens — the whole scene under a radiant azure sky that occurs only at high altitudes. And indeed we felt the altitude, especially later in the afternoon as we arrived at Camp Muir, Rainier’s base camp.

Muir is situated at over 10,000 feet on a wind-blasted rocky ridge, perched picturesquely above one of Rainier’s glaciers with a series of dangerous-looking crevasses dropping into shadowy depths. Every step we took had been labored and the desert-dry air induced the need for constant gulping of water from the four canteens we carried.

The plan was for climbers to sleep until midnight and then begin the final ascent to the summit. In summertime, the dark hours are the safer times in which to ascend through the snowfields and over the glaciers, before the high sun can melt masses of snow and set off avalanches.

Most of the party members were too pumped up with adrenaline to sleep and the couple who did snored loudly enough to be heard in Seattle. In any case — word came late in the evening that a storm was brewing just east of the mountain and was expected to hit around 1 a.m. — just when the climbing teams would be heading for the summit and so the climb had to be “turned” as the climbers’ expression has it. 

We were offered a second chance to try for the summit later in the summer — but all dates for the next few weeks were fully booked and so with a mixture of disappointment and relief we started down at sunrise.

We felt disappointment because, as we descended, the shimmering snowfields and glaciers against the cobalt-blue sky above Camp Muir were like the Sirens’ call — alluring almost beyond resistance; relief, because we knew we were not up to this challenge.

We were neither acclimated nor in physical shape for climbing above this altitude. Drained and dehydrated, we were sobered by the thought that we would have had nearly 4,000 more feet to ascend — roped together in teams and making our ways with ice axes — in the company of people who were far more fit than we were. 

And yet — though our trek on Rainier was terminated, it remains one of the greatest of all my life’s adventures and the memory of those two days on that magnificent mountain is its own success.

 

Pikes Peak

My next attempt at climbing at high altitudes came a year or so later when, at the invitation of some friends in Colorado, I began taking on the challenge of climbing some of Colorado’s “Fourteeners” — Rocky Mountains higher than 14,000 feet. 

The first mountain was going to be Pikes Peak with a massive profile that looms over the city of Colorado Springs. This time, I was determined to be more prepared and spent several days in the city itself getting acclimated to the elevation.

“The Springs” as the locals call it has an elevation of 6,300 feet — a thousand feet higher than the “Mile-high city” of Denver. And the setting is deceptive: Since “the Springs” lies at the base of 14,109-foot Pikes Peak and other high summits of the Rockies that rise like a gigantic wall above the city, the impression is created that its elevation is far lower than it actually is.

Travelers newly-arrived are unnerved to find that simple acts such as carrying a suitcase up a flight of stairs can leave them gasping for breath and their hearts pounding. As it happens, Colorado Springs has a paved running trail that meanders through the city’s outer neighborhoods, bordered by yucca and cactuses and other desert plants; it traverses moderately steep hills, making it an ideal course on which to get acclimated to the elevation.

I did a series of runs in the days before we set out for the mountain and was somewhat intimidated by the effort resulting from the lower oxygen levels.

The most popular trail to Pikes Peak’s summit departs from the neighboring town of Manitou Springs, a 27-mile-round-trip that most people do over two days. With backpacks and walking sticks, we set out early one morning following a series of switchbacks on a well-defined trail that led into the Pikes Peak wilderness.

Pikes Peak and many surrounding mountains are part of what geologists term a batholith — a gigantic mass of igneous rock, in this case a beautiful deep-red granite — that has been pushed forcefully from deep within the Earth.

As it rose, it broke through horizontal layers of russet iron-bearing sandstone, creating the spectacular tilted and sometimes vertical slabs of Denver’s Red Rocks Park and the Garden of the Gods in Colorado Springs. Wind, water, and glacial ice have subsequently sculpted the granite mountains into rugged summits, several of them —Pikes Peak included — high enough to retain snowfields even in the summer.

Our first day’s trek took us up through some wild forests in which mountain lions are known to roam, attacking solitary climbers. But on a summer’s day, “solitude” is not a state to be found anywhere on Pikes Peak and scores if not hundreds of people may be making the ascent — the most intrepid and fit completing the entire round trip in a single day.

We were seldom out of sight of other climbers and their echoing voices frequently distracted from the natural sounds of wind and birdsong in the stunted pines. We camped for the night at a very primitive but crowded campsite just above timberline at around 11,000 feet.

After nightfall, far below us, the lights of Manitou Springs and Colorado Springs were spread out toward the horizon in vast, vertiginous, glittering geometric patterns. High altitudes can inhibit both appetite and sleep, but with over 3,000 feet to ascend the next morning, before sliding into our bedrolls for a night of fitful slumber, we managed to chow down on high-protein food reconstituted with our mini-camp stoves. 

To our disappointment, the bright glow of the sprawling cities below tended to dim the light from the stars, which should have been brilliant at that elevation.

We were awakened from a restless sleep at dawn by the voices of literally dozens of other climbers for whom today was “summit day.” Fortunately, the changeable weather of the Front Range Rocky Mountains had given us a clear, dry morning.

We set out for the summit up a seemingly endless series of switchbacks; this meant slow upward progress but it also reduced the effect of the increasingly thinning atmosphere. In less than three hours, we arrived at the top — and were overwhelmed by the crowds.

Like Mount Washington and New York’s Whiteface, Pikes Peak has an auto road to its summit; also like Mount Washington, it has a cog railway to bring up tourists in great numbers. 

Some of them looked shaky, seriously affected by the rapid increase in altitude, and were looking for a place to sit down or were quickly returning to the cog railway car in which they had come up. The railroad allowed only 40 minutes on the summit for its passengers and even that was too much time for the unacclimated.

Heart palpitations, headaches, and nausea are common among people who venture into regions of thin air — even sometimes for those who are acclimated.

The sweeping view from the top inspired Katherine Lee Bates to compose “America the Beautiful”: To the east, the Great Plains stretched into the dusty distance; north and south, steep peaks and passes of the Front Range of the Rockies lumbered toward both Wyoming and New Mexico; to the west, rugged summits of the Sawatch Range and the Presidential Peaks receded into a blue haze.

But the noise from crowds and cars overwhelmed the scene, making it more a tourist attraction than a conquered summit, seemingly diminishing our effort to achieve it.

 

Mounting Massive

But the following summer, at the invitation of one of my former students, I accepted the challenge to climb Mount Massive, an enormous “Fourteener” that rises above the village of Leadville and the Animas River Valley west of Denver.

Massive is an isolated peak with a jagged summit and, like Mount Washington, it is known for its violently changeable weather even in summertime. At 14,421 feet, it is also the second highest mountain in the Rockies, rising a few miles north of Mount Elbert which is the highest.

Pikes Peak and the other soaring Rocky Mountains rose during the Laramide Orogeny, some 80 million years ago. But the rocks of which these mountains are made are far older — metamorphic rocks such as schist and igneous granite from Proterozoic time, some 2.5 billion years in the past.

As the Rockies are far from any tectonic plate boundary, the forces that caused the Laramide Orogeny are — as the saying goes — “not well understood,” but the result was a chain of peaks many of which are over three miles high, and Massive — as its name suggests — is one of the most impressive and challenging.

Our climb began at dawn at the end of a gravel road near the Colorado Trail, which heads south along the base of the Sawatch Range of the Rockies, passing through some very high, remote wilderness. Though it was July and the sky was a clear Colorado azure, the ground and the stunted tree trunks and foliage were covered in frost — common at this elevation even in summer.

We encountered no one else on the trail, but talked loudly and made every attempt to make noise as we walked, wary that these high forests are home to mountain lions and bears known at times to be aggressive. The path to the summit departed west from the Colorado Trail, and soon we were above timberline.

This trail was far different from the gentle switchbacks of Pikes Peak and every step became an effort as the air thinned; steep and sometimes poorly defined, the path reached upward past frost-blasted cliffs and outcrops of gneiss and granite and our footing became treacherous as we made our way over boulders and jagged piles of glacial debris.

Toward noon, what had been a mild morning breeze became a low, menacing wail and gradually the sky was dimming to a featureless gray haze. A rule of climbing in the Rockies is to make summit by 2 p.m.  because that is when the high sun can begin to breed storms from rising air currents and experienced climbers will begin their descents.

The top of Mount Massive is not a single point but an undulating plateau of nearly a half square mile with three ragged elevated points, the highest in the middle. We could see the actual summit only a few hundred feet away but in the thin air, even on a now much-gentler gradient it became an effort just to breathe and walk and we settled into a rhythm — 25 steps and a rest; 25 steps and a rest — until we reached the summit cairn lording over a rocky wilderness.

Though the cold wind had risen to an increasingly menacing howl, with our ascent over, it became pleasurable to be able to breathe without feeling we were gasping for oxygen. That climbers — some of them without oxygen canisters — ascend to twice this elevation in the Himalayas into what is called “the Death Zone” in temperatures well below zero was almost unthinkable.

We did not linger after snapping a few photos and headed back down through the stony wastes. The saying goes that a mountain is not climbed until you are down, and the view to the west where Massive’s notorious storms breed had become a deep, dirty gray that was slowly resolving itself into voluminous clouds.

Even at these altitudes, descending is much less taxing than ascending and it was a relief when we dropped below timberline into the Colorado forest. Though we heard a couple of rumbles of thunder as we made our way down from the trailhead and along the Colorado Trail, the full fury of the storm was not unleashed until we had returned to Leadville.

By then, all of Massive had vanished into ominous dark obscurity and when dawn broke the next morning the mountain gleamed under a fresh coating of snow that streamed from the summit in lacy filaments.  The prospect of having been caught in that storm was sobering indeed.

 

Legendary peaks

Over the years I have climbed six more of Colorado’s “Fourteeners,” none of them as daunting as Mount Massive, but each with its own alluring scenery and challenges.

I have also summited a number of peaks in the Canadian Rockies, lower than those in the United States but often still in the grip of extensive glaciers from the last ice age: Rising above meltwater lakes of stunning shades of turquoise, they are icy peaks covered in lichen-besplotched boulders from which tough little rodents called pikas and marmots whistle warnings to their companions; crystalline streams meander down through the rocky debris and vanish mysteriously into great fractures in the glaciers.

But there, too, the weather is shockingly changeable and sometimes on warm sunny afternoons the sudden odor of ozone in the air may accompany approaching lightning and a violent snowfall.

Yet I realize I have hiked only among the lower, more accommodating of the peaks that rise into Earth’s thin air. But I often read about expeditions into the legendary peaks that soar into the regions of the world above 25,000 feet with awe for those who venture there.

And sometimes I dream of snowy, wind-ravaged summits bedecked in Buddhist prayer flags where — arm-in-arm with Sherpas — only the bravest venture.

Location:

— Photo from National Park Service
Boxwork, at Wind Cave in South Dakota, is called cratework when it is this large.

A recurrent problem in geology is the sudden appearance of what researchers term a “leave-it.”

Surrounded by his grad students, a professor has examined a site; rock outcrops and sediments, and erosional or tectonic phenomena have been observed, and, following appropriate consideration of all of the facts, the professor proposes a theory to explain the site. 

Then someone — one of his grad students, or worse, someone with no geologic training whatsoever who just happens to be accompanying the researchers on their field excursion — picks up a rock, shows it to the professor, and says, “What’s this?”

It happens that “this” is the proverbial monkey-wrench in the works, the very presence of which undercuts the entire carefully-constructed theory of the site’s origin and history. After careful examination, the professor may toss the sample in hand once or twice and then give it a mighty heave, while mouthing the words — “Leave it!”

While there are undoubtedly more “leave-its” in New York State than many scientists would want to admit — and they are by no means confined to the geologic sciences — there are two in particular, one in Albany County and the other in the Adirondacks, worthy of consideration.

Interesting mysteries in themselves, they are also reminders of the fact that nature has many secrets, and human abilities to decipher them in the end are not without limits and should inspire humility in all science researchers.

 

The “Boxwork” rocks of the Clarksville Gorge

On the edge of the village of Clarksville is a gorge through which flows the Onesquethaw Creek. Cut millennia ago when the great glaciers were melting and the Onesquethaw was vastly more voluminous and powerful than it is today, the gorge features small caves and springs in rugged limestone cliffs towering over terraces pockmarked with potholes along with mounds of sediment carried down by the Onesquethaw from bedrock layers higher in elevation in the Helderbergs.

There are also pebbles and cobbles scraped from the bedrock and transported from the Adirondacks and regions above the Canadian border and then left in great deposits of sediments as the glaciers retreated. Such rocks are called “glacial erratics” and identifying their sources allows geologists to map the paths of advancing glaciers. The gorge is a veritable textbook of geologic processes.

Yet, among the chaos of sediments, a patient observer can find some curious rocks that are wildly out of place in this part of New York State and whose ultimate bedrock source is a mystery. The rusty-red sandstone rocks are found as jagged samples, their color revealing the presence of quantities of iron — the same element responsible for the color of the landscapes of Utah and the planet Mars.

But what makes the samples unusual is the fact that they are highly fractured, and the intersecting fractures are filled sheets of white quartz, formed from the silica that makes up much of the sandstone matrix and forced into the fractures under immense pressure.  Known to geologists as “boxwork,” structures such as this are sometimes found in caves such as Jewel Cave and Wind Cave in South Dakota.

But these caves are dissolved out of limestone — made largely from calcium carbonate — and the sheets that make up the boxwork are pure calcite, which is more resistant to weathering and erosion than the limestone and the “boxes” therefore tend to project from surfaces.

And the question arises: Where did these rocks come from? There are no rock layers in Albany County or the lands to the north in New York State whose bedrock is known to contain structures such as the boxwork in these samples.

Glacially-transported rocks are usually somewhat rounded off, their sharp corners abraded by slow grinding against other hard sediments within the ice.  Some of these rocks are partially rounded but many are jagged — though the presence of the angular “boxes” would likely result in fracturing rather than rounding.

And then there is the question of why these rocks are found in the Clarksville gorge of the Onesquethaw but are not reported from other sites in the Helderberg area or elsewhere in the state. “Leave-its” indeed!

 

The “Tafoni” of Snowy Mountain

Above Indian Lake in the Adirondacks looms Snowy Mountain. Rising to 3 898 feet above sea level, Snowy falls 102 feet short of being a true New York State “high peak.”

But it offers sweeping views of the surrounding mountains and lakes and its location west of many of the other soaring summits crowned by Mount Marcy make it less likely to be the goal of “peak baggers,” especially on weekdays. Snowy’s bedrock is a mélange of the rock types shared by most of the mountains of the Adirondack region: igneous and metamorphic rocks such as granite, gneiss, schist, gabbro, and anorthosite.

On a slope of Snowy Mountain and not far from a meandering highway is a collection of enormous boulders known as “tafoni.” The term is obscure; my dictionary of geologic terms published by the American Geological Institute does not even list it. According to Wikipedia, the word may be of Sicilian or Corsican origin and simply means “rocks with holes.”

On the other hand, the similar phenomenon known as “honeycomb weathering” is well known to geologists and found fairly commonly in the states of the “Four Corners” area in the Southwest. I recently photographed a textbook example along the highway known as the “Turquoise Trail” that runs southeast from Santa Fe, New Mexico.

Honeycomb weathering generally occurs in rock that contains or consists mainly of calcium carbonate — limestone and calcareous sandstone — and forms when the slight acidity of rainwater chemically dissolves the mineral randomly over centuries, producing the pockmarks.

Some igneous or metamorphic rocks also contain calcium carbonate or other minerals that may dissolve very slowly in natural acids but it is believed that sandblasting can also create honeycomb weathering. A combination of chemical weathering and sandblasting may well explain the tafoni of the Turquoise Trail outcrop and that of other sites in the Four Corners states.

New York’s tafoni lie in a heavily-wooded area on a fairly steep section of Snowy Mountain’s western slope: enormous boulders covered in mosses and fern gardens, pocked with pits of varying depth, some only a couple of inches in diameter, others big enough to walk into.

The larger hollows frequently have smaller pocks within them. Chalk markings and abrasions show that some of the largest have been climbed by boulderers and one has a rickety old ladder, allowing a precarious ascent to its top.

But the enormous tafoni of Snowy Mountain present a puzzling case. For one thing, the boulders do not contain calcium carbonate or any other mineral that dissolves readily, even when doused in hydrochloric acid.

They also are clearly not “in situ” — in other words, they are not weathered remnants of the slope on which they are located. They are somewhat rounded and they are not attached to the ground, clearly having been transported there either by tumbling from a higher location on the mountain or dumped there by glacial action.

But none of the cliffs and other exposures of the bedrock of Snowy Mountain show honeycomb weathering and there are no expanses of bedrock north of the mountain in the Adirondacks that are known to yield boulders that have weathered into tafoni.

Moreover, they are surrounded by thick forest, which would seem to preclude sandblasting as the cause of the pits, although in millennia past, in the wake of the glaciers, the slope would have been barren of protecting forest cover. In any case, the question arises — as with the boxwork rocks of the Clarksville gorge — where did the tafoni come from and how did the pits form?

Perhaps the solutions lie in the future in the research of graduate students completing theses for degrees.

In the film “Jurassic Park,” a biologist, contemplating the ingenuity of the dinosaurs, utters the famous line, “Life will find a way.”

And Earth’s restless crust and the great forces that churn beneath it also frequently confound science. Two-hundred years ago, most scientists and scholars believed that our planet was 6,000 years old and that all the great changes that had shaped its surface were divinely directed. 

A hundred years ago, before the theory of plate tectonics was backed with irrefutable evidence and accepted as the cornerstone of modern geology, Alfred Wegener was almost universally derided for the notion that the Earth’s continents and seafloors moved around its surface like giant rafts.

And, among many other mysteries in modern science, geologists and biologists alike are intrigued by the source of the methane being detected emanating from the surfaces of Mars and Saturn’s moon Enceladus.

Mother Nature clearly does not play by our established “rules” and has many more mysteries — and surprises — in store for us yet.

tufa bedrock

The Enterprise — Mike Nardacci
A weathered section of tufa bedrock shows some of the many arches and overhangs.

Situated in the picturesque village of Vanhornesville west of Albany is a display of unique geologic features called “tufa caves” that — along with the village itself — are likely unknown to most people in the upstate area.

Located to the north of Route 20, Vanhornesville is accessible by State Highway 80, about a relaxed 90-minute drive from Albany, passing through farmland and woods as the roads traverse gentle hills.  There are no signs along the way to announce the caves and only a couple of small ones within the village itself to point the way to the Outdoor Learning Center of the Owen D. Young Central School District, the preserve in which the caves have formed.

When most people think of caves, they are undoubtedly thinking of what geologists call “solutional caves,” such as the nearby commercialized Howe Caverns and Secret Caverns and the many wild caves that underlie the Helderberg and Cobleskill plateaus west of Albany.

Solutional caves are the product of the dissolving of carbonate bedrock such as limestone or marble by mild natural acids, most commonly carbonic acid. This acid forms when falling rain picks up carbon dioxide in the atmosphere or when pooled surface water absorbs the gas from decaying plant material.

It is an extraordinarily slow process and great solutional caves such as Mammoth Cave in Kentucky can take millions of years to form.

Other common cave types are fracture caves, caused by the gradual enlargement through erosion and weathering of natural joints in cliff faces; lava caves such as those in Hawaii formed by erupting volcanoes; and what are called “talus caves,” which are essentially enterable spaces between massive boulders that accumulate at the base of a cliff as a result of landslides. These caves are often scorned by sport cavers as “just a pile of rocks,” though geologists find they often contain complex and unique geologic features.

But tufa caves are relatively uncommon and are rarely very extensive, measured in feet rather than miles, unlike solutional caves that can extend for hundreds of miles. Nonetheless, like the tufa caves of Vanhornesville, they have their own attractions, one of which is that many of them require no special equipment to explore beyond a flashlight, and some are shallow enough that even that is unnecessary, though a helmet is recommended if an explorer wants to avoid bumping one’s head.

And the very process by which tufa caves are made is of interest, for, unlike solutional and fracture caves that form in pre-existing bedrock, tufa caves develop from the chemical deposition of rock from flowing mineral-saturated water.

Anyone who has visited a commercial cave has learned the mnemonic regarding the calcite formations that appear there: stalactites — there is a “c” for “ceiling,” and stalagmites — there is a “g” for “ground,” indicating the places where they form.

It is an oversimplification to say that they form from “dripping water,” though that is certainly more accurate than the explanations of the ancient Greeks and Romans who believed that they were some bizarre form of life and were literally “growing” in the cave environment.

But in fact what appears to be pure water dripping from the cave ceiling is a solution of calcium bicarbonate containing dissolved carbon dioxide that stays in solution as long as that liquid is within the confines of narrow fissures through which it is being pulled downward through the bedrock by gravity. 

When the droplets emerge into the cave environment, the decrease in pressure causes the solution to “de-gas” — similar to what happens when the top is removed from a carbonated beverage — releasing the carbon dioxide and depositing a minute amount of calcium carbonate on the ceiling or on the floor.

The agitation of that liquid as it flows down the cave wall or splashes onto the floor can also cause it to de-gas, much as shaking a carbonated beverage may cause the carbon dioxide to de-gas forcefully. Over long periods of time, the result will be the growth of stalactites, stalagmites, flowstone cascades, and other cave formations.

But under certain conditions, the stream in a karst aquifer — a technical name for a solutional cave with flowing water — may itself contain large amounts of dissolved calcium carbonate and is either super-saturated or under sufficient pressure that the “degassing” process does not occur until the stream emerges from the bedrock and flows over the surface.

At that point, the deposition of calcium carbonate — calcite — will occur as the pressure is released or the saturated water mixes with plain H20 and anything in the stream’s path may become thickly coated with these deposits which are known as “tufa.” The resultant rock tends to be relatively soft and crumbly and porous and often has the appearance of petrified shaving cream, sometimes containing mineral-coated sticks and twigs and leaf impressions.

Along the section of Route 146 that runs parallel to the base of Barton Hill near Gallupville there are a number of streams resurging from small caves at the base of the cliff and in times of low flow those streams will deposit tufa, which may appear as a white coating on rocks in the streambed or form pebbles and cobbles containing sticks and twigs and leaf impressions.

A more dramatic example of this deposition can be seen on the north side of Route 443 between Gallupville and Shutters Corners. An extensive section of the hillside is covered with conglomerate — a naturally-cemented mass of rock fragments.

Here, long ago, tufa springs emerging from the cliff above cemented extensive deposits of glacial debris — or “drift” — and formed the conglomerate. These mineral springs eventually sealed themselves up and no longer flow. Today the conglomerate is fracturing and weathering away and may eventually cause a landslide onto Route 443.

The caves at Vanhornesville have formed a series of tufa deposits in a narrow valley that contains the Otsquago Creek. Saturated with calcium carbonate, the stream’s headwaters emerge from a series of springs and deposit the mineral.

At some point in the past, undoubtedly due to the melting of the glaciers at the end of the ice age, the stream carried a far greater volume of mineral-saturated water than it does today, resulting in the massive outcrops of tufa with their irregular, intricate openings: overhangs and tunnels and arches.

But unlike solutional caves, which can take millions of years to develop, these tufa caves are relatively young in geologic terms and are certainly post-glacial. Given the relative softness of tufa, the grinding effect of the continental glacier advancing over the landscape would have ground them away — although there might well have been an earlier series of caves that the glacier destroyed.

The porosity of the tufa allows it to hold water and makes it a perfect environment for moisture-loving plants. The walls and nooks and crannies of the Vanhornesville caves thus are covered with mosses, lichens, various types of ferns, and rare wildflowers in spring.

Though the entrances to the numerous little caves appear mysteriously alluring, upon entering one, the visitor quickly understands the adage, “What you see is what you get,” and there is no danger of getting lost in an underground labyrinth.

But to hike in and around the caves with their quirky, mossy, storybook ambience is to experience a unique example of what nature can create with time and some simple chemistry.

— Photo by Mike Nardacci
The view south from the trail to The Snow Hole shows Berlin Mountain rising in the center, the highest point in Rensselaer County.

— Photo by Mike Nardacci
The shady, moss-lined Snow Hole resembles a limestone sink hole. Except during mid-summer, its floor never receives sunlight and traps winter's cold air.

— Photo by Mike Nardacci
Research assistant Devin Delevan holds an ice ball made from snow compressed at the bottom of the fissure.

"Fat Man's Misery" in Thacher Park

This archival photo of "Fat Man's Misery" in Thacher Park shows how weathering agents have separated a huge section of the cliff from the bedrock; the force of gravity will someday cause it to crash down to the talus slope beneath it.

To cross the Hudson River and head east on routes 43 or 2 or 7 onto the Rensselaer Plateau is to enter a landscape vastly different both geologically and topographically from that west of the river.

The Mohawk-Hudson lowlands stretching from Albany north to the shores of Lake George are composed of sand deposited on the shore of glacial Lake Albany, which formed over 10,000 years ago at the end of the last ice age and feature low, rolling hills and scattered lakes formed from glacial meltwater. 

To the west and south of Albany rises the northernmost section of the Appalachian Plateau — called “the Helderberg Plateau” or simply “the Helderbergs” locally — consisting of mostly flat layers of sedimentary rock: sandstone, shale, and limestone deposited in the late Silurian and Devonian Periods of geologic history. Famous throughout the world to geologists, the layers — or “strata” — contain a vast collection of fossils of ancient species and have been called “the key to the geology of North America.” 

The strata that once lay under the sea were elevated by plate tectonic movements during the “Appalachian Orogeny” some 290 million years ago when the land masses that would eventually be known as Europe and North America crashed together in the formation of the super-continent we call Pangaea. East of the river, Ordovician-age rocks took the full force of the collision, and were compressed, folded, and elevated much as the hoods of two colliding cars would be; to the west the Appalachian Plateau was elevated but little deformed — much, say, as the rear parts of the crashing cars might be pushed up above the chassis. 

There was a time far earlier — some 475 million years ago — when the east coast of what would eventually become North America was located somewhere near what is today the Hudson Valley.  It collided with another land mass consisting of volcanic islands in the great event called the Taconian Orogeny, pushing up mountains that may once have been as high as the Himalaya. Imagine today looking east from Troy and Albany and seeing a range of jagged, snow-capped peaks over 20,000 feet high!

Deep within these mountains, pressures were unimaginable and the rocks there were twisted and distorted and the resultant heat cooked the rocks in the process known as “metamorphism,” forming new minerals and rock types: slate, phyllite, gneiss, and schist, often laced with thick veins of milky quartz. Excellent displays are visible in Petersburg Pass on Route 2 not far from Williamstown.

But the inexorable forces of weathering and erosion — rain, wind, and sculpting glaciers — tore away at the peaks over millions of years. Their remnants in our part of the world — a series of much lower, often steep-sided knobs and ridges — are often called “the Berkshire Hills,” though Berlin Mountain above Petersburg Pass is a very respectable 2,818 feet in elevation, the highest point in Rensselaer County. 

Examine the bedrock that is exposed in the pass — or bordering the ski trails on the summit of its neighbor to the south, Jiminy Peak — and you will find twisted and distorted cliffs and ravine walls of heavily fractured phyllite, a metamorphosed form of shale.

Both Jiminy Peak and Berlin Mountain are features of the Taconic Crest Trail, a 37-mile-long hiking path stretching from south to north, weaving in and out of New York, Massachusetts, and Vermont. Extending 60 miles or more on clear days, views from it are often stunning, especially in the fall when the hardwood trees that cover the surrounding slopes put on their spectacular colors.

 

The hike

From a parking lot on the high point of Route 2 at Petersburg Pass near where the borders of New York, Massachusetts, and Vermont come together, one segment of the Taconic Crest Trail leads south to Berlin Mountain. Another moderately challenging portion of the trail begins on the north side of the highway, leading to the curious feature known as “The Snow Hole”; it can be done as part of a much longer day hike starting farther south or as a 5-mile round trip from the parking lot.

Its ups and downs are for the most part not particularly steep — but as a friend of mine remarked, “It’s just that there are an awful lot of them!” In other words, good hiking shoes and perhaps a walking stick along with water and trail snacks are necessities and, given the often changeable weather, a rain slick is a good idea in warmer months. In winter, the trail is a superb and challenging snowshoe hike, but winds on the Taconic Crest Trail can be fierce and mandate a warm parka.

A steep but short pitch at the start of the trail soon begins to level out and offers an impressive view of the summit of Berlin Mountain and of the eastern and western slopes of Petersburg Pass. Though today the slopes are thickly overgrown with hardwoods, sporadically from 1962 until around 1980 there were trails here for downhill skiing at what was called Petersburg Pass Ski Center. 

On clear days, the ski trails of Jiminy Peak and Bousquet may be visible, as well as the rhythmically rising and falling Berkshires to the east and the Helderberg Plateau to the west. A glance at a topographic map of the area shows that the trail runs first along the side of and then on top of a narrow, steep-sided ridge geologists call an arete.

Aretes form in areas previously glaciated when glaciers descend from opposite sides of a mountain, creating the feature that is also sometimes called a “knife edge.” The knife edge on Maine’s Mount Katahdin is undoubtedly the best-known in the east and has long been a heart-pounding challenge for climbers.

But the arete en route to The Snow Hole is far more user-friendly; it is broader and that fact and the thick forests of maple, oak, and paper-birch that cover the slopes bordering this trail prevent any dangerous exposure. There are occasional herd paths that wander from the trail, but the main route is wide and well-marked.

A hard-to-find side path departs from the trail at one point, leading upwards to a feature called “Jim Smith Hill.” This is supposedly named for the “James Smith Club” the main requirement for joining this national social organization is to be named “James Smith” (variant spellings of the names are allowed). Why this bump on the ridge was so named is as obscure as the feature itself.

The trail subsequently passes through a constantly changing variety of meadows and forests with occasional long views to the southern stretch of the Berkshires and west to Albany before reaching a loop trail marked by a sign directing hikers to “The Snow Hole.” After a few hundred feet, the trail begins to descend the north side of the ridge leading to a feature that looks for all the world like one of the sinkholes in the limestone karst areas of Albany or Schoharie counties.

 

The Snow Hole

The Snow Hole is a vertical fissure in the bedrock lined with mosses and other moisture-loving plants.  One end offers a fairly easy descent to the bottom while the other end is a precipitous 60-foot drop. But the fissure is narrow enough and deep enough that its bottom never gets direct sunlight — and that leads to the conditions from which it gets its name.

Well into summer and occasionally into early fall, the bottom of The Snow Hole has a thick deposit of ice formed from pressure exerted by the deep snows that accumulate on the higher summits of the Berkshires during their long winters.

Sinkholes form commonly in carbonate bedrock such as limestone and marble when mildly acidic water from rainfall or runoff percolates through fissures and dissolves the rock, often feeding cave systems below. But The Snow Hole is what is known as a tectonic feature, formed by physical forces.

The steep slope of the ridge contains extensive cracks in its bedrock known as joints that run parallel to the ridge line. Over millennia, water and ice have eroded this fissure and, because it is located on the very steep north slope of the ridge, it has widened and deepened under the pull of gravity. Several much narrower fissures are found between The Snow Hole and the main ridge trail.

Another result of these same processes can be found in Thacher Park at the narrow cleft in the rock known for a century as “Fat Man’s Misery,” which offers access to the trail leading to Hailes Cave though it does not collect lingering snow. A massive section of the limestone has separated from the cliff and gravity has pulled it away sufficiently to allow slender hikers to traverse it. Someday it will tumble from the cliff and crash onto the talus slope below as have many such masses before it.

And this is the fate that ultimately awaits The Snow Hole of Petersburg Pass. Over time, the accumulating snows within it will continue to be compressed into ice, which will further deepen and enlarge the fissure; as the steep hillside is carved away by the agents of erosion the outer wall will collapse and become part of the talus slope that falls away into Vermont.

But there is another fissure between The Snow Hole and the top of the ridge that will also continue to deepen and widen — and some millennia from now it may become the next Snow Hole as the forces of weathering and erosion continue their relentless assault on the ancient bedrock of the Berkshires.

 

Location:

The Enterprise — Mike Nardacci

Rocks in one of the many stone walls in the Helderbergs are easily forced out in winter frosts, creating gaps.

The Enterprise — Mike Nardacci

Potholes are ubiquitous during the seasonal changes from winter to spring, but this one is particularly deep.

The Enterprise — Mike Nardacci

The cliff behind the ice column that forms annually at Thacher Park is laced with fractures that expand and release rock fragments in winter and early spring.

The Enterprise — Mike Nardacci

A multi-ton boulder of hard metamorphic rock has been cleft in two by ice that formed and expanded in a fracture.

The Enterprise — Mike Nardacci

Due to frost wedging, great slabs of rock have spalled from this limestone outcrop south of the village of New Salem, forming a steep cliff.

The Enterprise — Mike Nardacci

Along the Beaver Dam Road, this exposure of the Esopus shale is gradually being reduced to gravel by frost action.

The Enterprise — Mike Nardacci

The impressive profile of Potash Mountain looming above Lake Luzerne formed when several small glaciers descending from its summit carved its pyramidal shape.

“Something there is that doesn’t love a wall,” Robert Frost wrote, “That sends the frozen ground swell under it,/And spills the upper boulders in the sun,/ And makes gaps even two can pass abreast.”

Of course — Robert Frost being Robert Frost — the astute reader soon realizes that the “something” to which he is alluding is a symbolic force beyond the natural one of a frost heave. “Frost is writing about something other than FROST,” a professor of mine once told our class, a statement fraught with multiple meanings. 

Nevertheless, this time of year the natural — and frequently destructive — effects of the past winter’s ice are in evidence just about anywhere one cares to look — perhaps most annoyingly in our pock-mocked city streets and country roads.

Appearing first as fine lines often resembling the strands in a spider’s web, fractures caused by the natural wear and tear of moving traffic begin to lengthen and interconnect, producing jagged pieces of gravel and leaving behind little indentations; these then also interconnect and become even larger pits which fill with water — and then the tire of your car hits what looked like a shallow puddle in the road followed by a sickening thud and the shuddering of both car and occupants.

And the culprit is frozen water — or, rather, the alternate freezing and thawing of water, phenomena that occur throughout the winter at our latitudes but become particularly frequent and destructive when winter begins to loosen its grip. 

The phase change of water from liquid to solid and back again wreaks destruction on any exposed porous surface and occurs repeatedly throughout the seasonal transition.

“Stay where you are until our backs are turned!” is what Robert Frost calls the “spell” to keep boulders in a stone wall in place, though the words themselves betray their futility. How often in February do we see work crews filling in potholes with steaming blacktop — only to have the fill ripped out and scattered forlornly over the road surface following the next snowfall or slush storm?

When torrential floods or massive snowstorms occur, we become all too aware of water’s destructive power in its various states, but because of its ubiquitous nature, we otherwise tend to take it for granted.  However, among many other ancient people, the Egyptians knew that their civilization depended upon the water in their great river — Egypt being “the gift of the Nile” — and they worshipped a god called Hapi as its spiritual embodiment; ancient Greeks built temples over springs, whose waters were considered not only essential for life but sacred.

Water is weird

But outside of a science classroom, we often tend to forget just what weird stuff water is. Reversing the behavior of other natural substances, water occupies greater volume as a solid than as a liquid, which is why a can of soda or a bottle of beer placed in a freezer will shatter when the liquid expands as it freezes;  likewise, unlike other substances, its density decreases when it becomes a solid.

And the phase changes of water involve amazing numbers of calories. Physics students know that, while it takes only one calorie of heat to raise one gram of liquid water by one degree Celsius, it takes 540 calories to vaporize that one gram when it reaches 100 degrees Celsius.

Take one calorie out of a gram and its temperature will drop by one degree — but if that gram of water is at zero Celsius, 80 calories must be removed to make it freeze. As it does, it will expand and become less dense, which is why ice floats.

And a good thing it does — for if ice were denser than water it would sink, causing many of our ponds and lakes to freeze solid in winter, wiping out all the life within them.

Most vitally, water is the absolutely essential ingredient for the existence of life as we know it, which is why the scientists known as “exo-biologists” are excited by the prospect of subsurface oceans on the moons known as Europa and Enceladus that orbit Jupiter and Saturn respectively.

Several years back, an early-season hiker on the Indian Ladder Trail at Thacher State Park was injured by a falling cobble-sized rock ripped from the cliff by winter’s ice, resulting in an extended closure of the trail. Apparently trying to conjure images of a dark conspiracy, an area daily newspaper subsequently published a story with a headline to the effect that the park maintenance staff “knew of” the danger beforehand. 

Of course they did — and so did every kid in New York State taking Earth Science! The implication that “something should have been done” is ludicrous. The mile-long trail follows the base of a cliff made of several different rock types, all of which are heavily fractured through natural weathering processes and all of which absorb water that freezes in winter, resulting in the shattering of rock known as “frost wedging.”

A photo taken in the Adirondacks shows a multi-ton boulder of the metamorphic rock known as schist that has been cleaved by this process. No amount of vigilance before the Indian Ladder Trail opened for the season could have accounted for every single crevice or fracture that was in danger of releasing a rock fragment.

The Helderberg escarpment has been eroding for millions of years, and the process will continue for millennia to come.  The broad talus slope that descends from the escarpment into the valley below is made up of billions of tons of rock weathered from it, ranging in size from giant boulders to sand grains — and these fragments do not fall without violent results.

The rocks of the Helderbegs generally fall into one of three types of sedimentary rock, formed hundreds of millions of years ago in the seas of the Devonian Period: limestone, shale, and sandstone.

Of the three, because of its density, limestone is generally the most resistant to weathering by frost wedging, though natural acids in rain and groundwater will cause it to dissolve. From a limestone outcrop south of the village of New Salem, great slabs of rock have been wedged by ice accumulating in the natural fractures in bedrock known as “joint partings,” forming a steep cliff .

Shale is petrified clay and can easily absorb water that can cause a solid rock exposure like one on the Beaver Dam Road above Thacher Park to be reduced to a pile of gravel by frost wedging. The talus slope below the the Helderberg escarpment is formed mostly from the on-site weathering of porous shale and sandstone bedrock, though it is littered with immense jagged boulders of the Manlius and Coeymans limestone layers that have broken away from the cliffs and gone crashing down from the plateau.

Ice Age changes

Much of New York State’s landscape was changed radically starting 1.5 million years ago with the onset of the Pleistocene Epoch, more commonly known as “the Ice Age,” though it was only the most recent of several that Earth has experienced over the billions of years of its existence.

In the Helderberg area, the steep faces and flat tops of Bennett Hill in Clarksville and Vroman’s Nose in Middleburgh show the effects of the movement of the continental ice sheet. Laden with rock fragments torn from bedrock by frost action, the glaciers acted like gigantic bulldozers sculpting and scraping the bedrock, often with spectacular results.

Pyramidal Potash Mountain that looms above Lake Luzerne got its unique shape when several small glaciers descending from its summit tore away its dense metamorphic bedrock.  Had the glaciers persisted for a few more thousands of years, Potash Mountain might have become a miniature version of Switzerland’s Matterhorn.

A graph of daily temperatures as the year in the Northeast progresses from January to June would show a constant variation from cold to warm and back to cold again. It must be remembered that an “average” temperature is simply the mean between two extremes, and it is not unusual in this part of the country to have a day in the 70s in February and a snowy day in May — though the general temperature trend obviously is upward.  

Warm days and below-freezing nights are said to be ideal for maple syruping. But they certainly can wreak hell on our roads and rocks.

Location:

— Photo by Mike Nardacci

Commemorating James and Guildford Otto who died in the Civil War, this severely weathered marble monument stands on a sunny hillside in the Town of Rose Cemetery and has always saddened the Nardacci family.

— Photo by Mike Nardacci

The impressive, near-pristine Briggs family monument, carved from gray granite still shows high polish after more than 100 years of exposure to weathering in the Town of Rose Cemetery.

— Photo by Mike Nardacci

Many marble headstones in Knox’s High Point Cemetery, with its elegant gateway, are still legible, due largely to the cemetery’s dry, sunny location.

— Photo by Mike Nardacci

Toppled stones gathered in a humid, shady portion of High Point Cemetery are heavily weathered, their inscriptions largely erased.

— Photo by Mike Nardacci

The Reidsville Cemetery with its wrought-iron gate seems the quintessential Helderberg burying ground.

— Photo by Mike Nardacci

The towering evergreens of the Reidsville Cemetery create a dark, humid environment conducive to many agents of weathering, destructive even to very hard rock such as granite.

Someone once described the goldenrod that seems ubiquitous this autumn as “quill pens signing summer’s eviction notice.”  Whether it was the blooming of goldenrod or some other harbinger of summer’s end that inspired the autumnal imagery of his classic, melancholy “Elegy Written in a Country Churchyard,” English poet Thomas Gray wandered through a rural cemetery “Far from the madding crowd’s ignoble strife” and in the evocative silence brooded over the lives of the souls interred there.

From their names and fleeting scraps of information carved on their tombstones, Gray inferred details of their triumphs and tragedies, their loves and losses, and their aspirations and failures, now marveling at the longevity of some or mourning the brevity of the lives of others. He read more into the moss-encrusted stones than most observers would — or would care to.

But it is a little-known fact that, to generations of geology professors, country cemeteries have frequently served as outdoor laboratories for the demonstration of many aspects of the cycles of weathering and erosion.

These are points that can, of course, be easily made using a textbook with its graphs and photographs.  But geology — perhaps more so than any of the other natural sciences except for biology — is best taught as a field science.

This is a fact that I can personally attest to from memorable courses I have taken at Acadia National Park, the Grand Canyon, Mammoth Cave, and other venues in which the complexities of the effects of mineral content, climate, exposure, and age on the weather-erosion cycle are clearly displayed.

And in a number of those courses, the professors packed students into vans and shuttled us off to old country cemeteries in which whatever geologic principle being taught was clearly and sometimes dramatically displayed.

The idea for this article came to me on a hot day in late August during a visit to the Town of Rose Cemetery in western New York in which some of my mother’s ancestors are buried. The cemetery sits on the slope of a drumlin, a glacially-deposited hill that is one of hundreds scattered across much of western New York and the Northeast. 

Drumlins and related glacially-formed hills called kames have frequently served as the locations of cemeteries, partially because their elevation above the surrounding landscape has symbolic meanings, but also because their composition of an unconsolidated mixture of soils and rocks makes them well-drained — ideal for burials.

One thinks of the high and windy hill that is the site of the Grover’s Corners cemetery in the melancholy third act of Thornton Wilder’s classic play “Our Town.”

Perhaps it is partly the inevitable association of cemeteries with Halloween that evokes their solemn atmosphere, and in this one even on a bright late-summer day there was a particular monument that has always saddened our family.

It stands a little over five feet tall and is carved from white Vermont marble, a very ancient rock formed during the Ordovician Period, some 450 million years ago, during the event known as the Taconian Orogeny.

The ancient ocean known as the Iapetus that lay off what is now the east coast of the United States was beginning to close as the process known as plate tectonics brought small land masses into collision with it, pushing up mountains and forming marble through metamorphism of pre-existing limestone.

Next to the monument, a bronze receptacle holds a flag, indicating that two of the dead memorialized here — my mother’s great uncles — died in the Civil War. The young men were inspired by the powerful words of  “The Battle Hymn of the Republic” — “As [Jesus] died to make men holy/Let us die to make men free.”

Their tombstone records that one of them named James Otto starved to death and was buried in Andersonville, the infamous Confederate prison in Georgia; the other, his brother Guilford, is actually interred here.  He and a fellow soldier were murdered by a Pennsylvania farmer with pro-slavery sympathies when they were sent to him purchase horses for the troops.

The memorial must have been splendid when it was erected around 1865. Today, the graven inscriptions recording the young men’s sacrifices have become difficult to read. In a decade or two, the inscription will be obliterated and it will stand as do so many other old marble headstones and monuments, their honored dead anonymous.

Marble is a very hard, dense rock that resists the absorption of water from rain or melting snow and therefore does not easily break down due to freezing and subsequent thawing in the process known as physical weathering; however, marble is composed of calcium carbonate, and as any high school chemistry student knows, calcium carbonate dissolves in acid.

Falling rain and fog pick up minute amounts of carbon dioxide from the atmosphere, producing a mild solution of carbonic acid. Ordinarily, carbonic acid of this strength is harmless to plants and animals but over many years it will slowly but relentlessly dissolve any calcium carbonate surface in a process known as chemical weathering.

Consequently, given that the monument was erected in Rose Cemetery over 150 years ago, it is surprising that the inscriptions are legible at all. But their saving grace has been the fact that the monument is situated on an open slope facing south, which means they are exposed to sunlight virtually all day when the sun is not obscured by clouds.

This results in the constant warming and drying of the surface, preventing its rapid dissolution and largely preventing growth of lichens and moss — the same factor that causes them to grow mainly on the north side of trees. They secrete small amounts of natural acids that in a damper, more sheltered environment can wreak havoc on organic or mineral surfaces — such as marble headstones.

Farther up the slope is another monument marking the graves of some other ancestors — in this case, my mother’s great-grandparents, whose surname was Briggs.

It was carved from gray granite, an igneous rock brought perhaps from New Hampshire or Maine and formed during the Devonian Period, in an event known as the Acadian Orogeny, some 380 million years ago; at that time, an ancient landmass known as Avalon — which would eventually become Europe — was subducting under North America and creating massive amounts of igneous rock through explosive volcanic action.

The monument stands over five feet tall and its rectangular base holds a massive sphere, an unusual design in this relatively modest graveyard. But although it, too, is over 100 years old, from its appearance one might think it had been placed there last week.

The sphere and the sides of the monument were highly polished and on a sunny day the reflection from the sphere can be blinding. Granite’s two major constituents are visible crystals of feldspar and quartz, both of which are capable of appearing in a spectrum of colors, though varying shades of pink and gray are most common.

The important fact is that neither of these minerals is easily susceptible to chemical weathering and given the extreme hardness and density of the stone and its openness to sunlight, even after a century the monument looks as fresh as if it had been erected very recently.

Almost all of the older headstones and monuments in the Rose Cemetery are carved from either marble or granite and their presence tells another story. Neither of these stones is found locally near the Rose Cemetery; they must have been imported from out of state and their inscriptions carved painstakingly by hand — which bespeaks the affluence of many of the cemetery’s silent residents and their families.

Contrast this one with many of the mossy pioneer cemeteries scattered throughout the Helderbergs in which many of the headstones of the hard-working people buried there were carved either from the native limestone or the local somewhat porous sandstone — both dating from the Devonian Period — and observe how the names of the deceased and their memorial inscriptions have largely vanished.

However, the High Point Cemetery above Altamont on Old West Road with its elegant entrance gate and meticulously-constructed stone wall is another example of a southerly-facing country graveyard in which both marble and limestone monuments a century or more old are still well-preserved.

Many of these stones are carved from marble but they face the southwest, and the view across Old West Road to a wide field is unobstructed by trees; consequently, the stones are dried and warmed from sunrise to sunset on days when the sky is not mostly overcast.

Many of the headstones are on a gentle slope and apparently were never set into concrete bases, and as a result they show the tilting common among monuments in older cemeteries caused by the slow, steady downward movement of the ground known as soil creep.

Frequently, in older cemeteries, this can cause the stones to topple, but High Point Cemetery is obviously lovingly maintained, its grass trimmed and even its very old headstones mostly upright. 

However, a collection of toppled, heavily-weathered markers in the shaded rear of the cemetery has been set aside against the old stone wall, their inscriptions mostly vanished along with record of the deceased they were intended to memorialize.

And, in a few cases, small, closely-spaced, rough-cut markers without inscriptions — harvested, perhaps, from tilled fields or pulled from stone walls — tell sad stories of deceased infants.

Shade can help to speed the forces of weathering and erosion in a humid, changeable climate such as ours — and a prime example is the venerable old cemetery near Reidsville.

With its ancient, very tall balsams and spruces, the cemetery is situated behind an evocative, slightly rusted cast-iron fence — the stereotypical locale for a Gothic ghost story. In the late 1800s and early 1900s, Reidsville was a village with a population of over a thousand.

Largely due to the quarrying activities that supplied the attractive sandstone known as Helderberg bluestone to many localities in the Albany area, the village grew, at one time boasting a hotel, a popular tavern, two churches, two retail stores, and a blacksmith shop — traces of which have largely disappeared.

The quality of the granite and marble stone monuments in the cemetery is once again evidence of the relative affluence of its occupants. Yet, although the majority of the headstones face east and could therefore be expected to get drying sunlight at least in the morning, the immense trees cast much of the cemetery into shadow and their thick boughs steadily drip moisture from rain and melting snow.

Some of the trees show the growth of the lichen commonly known as “Old Man’s Beard,” which resembles Spanish moss and flourishes in very humid boreal forests, especially those near great bodies of water such as the Acadian Coast of Maine and Canada. The damp, pitted ground surrounding many of the old headstones is deep with mosses, which do not flourish in sunlight.

As a result, even some once-stately granite monuments show evidence of heavy chemical weathering and are stained by dark lichens.  The contrast between them and some equally old, much-less-weathered stones in the more open rear sections of the cemetery is sharp.

And especially on a gloomy autumn day, the scene epitomizes Thomas Gray’s lines:

“Beneath those rugged elms, 

   that yew-tree’s shade

Where heaves the turf

   in many a mould’ring heap’

Each in his narrow cell

   forever laid,

The rude forefathers

   of the hamlet sleep.”

(In Gray’s time, the word “rude” had nothing to do with manners but rather denoted “unsophisticated.”)

In recent decades, upright stone grave markers have largely gone out of fashion due to the great expense of preparing them and in many newer areas of cemeteries they are prohibited, replaced by bronze markers which lie flat upon the ground.

An alloy of copper and other metals, bronze tends to resist chemical dissolution although after decades of exposure to moisture it may weather to a dull shade of green like a copper penny. But being at ground level, if not carefully maintained, these markers can soon be covered by grasses and weeds, hiding their inscriptions as surely as if they had been dissolved away.

A walk through a cemetery, especially one with familiar names on the memorials, may bespeak many aspects of the history of a town and its inhabitants along with many other profound thoughts that cemeteries are supposed to bring.

But a close examination of its location, the composition of its monuments and their condition reveals much about its geologic history as well: accounts of continental collisions, ancient rock changing through metamorphism, new rock forming from violent volcanic eruptions, and the much more recent passage of the great ice sheets. In all — a veritable textbook of geology.

Location:

— Photo by Mike Nardacci

Into the precipitous tufa cliffs of the Puye mesa, ancient people carved shallow caves as dwelling places with staircases and walkways to connect them.

— Photo by Mike Nardacci

Atop the mesa, free-standing buildings of Puye Pueblo have survived for centuries due to their durable construction and the dry climate. Thousand-year-old timbers support ceilings and upper floors and their shadows form intricate patterns on the ruined walls.

— Photo by Mike Nardacci

The ground at Puye is littered with obsidian fragments and with thousands of fragments of pottery from different time periods in the pueblo’s history.

— Photo by Mike Nardacci

The unearthly landscape around Acoma Pueblo is studded with mesas, buttes, and pinnacles eroded over millennia from thick layers of sandstone.

— Photo by Mike Nardacci

From a distance, the adobe dwellings of Acoma look like jagged boulders piled atop the mesa.

— Photo by Mike Nardacci

The beautiful church of St. Estaban is a masterpiece of adobe architecture.

— Photo by Mike Nardacci

In the Acoma visitors’ center are cases displaying the intricately-painted pottery for which the pueblo has long been famous.

— Photo by Mike Nardacci

Traditional dwellings in Acoma has upper levels accessed by ladders. The ones on the right are topped with struts carved to represent thunderbolts.

— Photo by Mike Nardacci

Reservoirs like this one supplied ancient residents with water from rain and snowmelt. Next to it is the only tree that grows on the mesa.

Northern New Mexico and the “Four Corners” area of the Southwest are dotted with ruins of the ancient pueblo people whose sudden evacuation of their traditional villages some 800 years ago constitutes a major mystery in the archeology of pre-Columbian America.

Modern pueblo people have oral traditions that connect their ancestors, often grouped under the term “Anasazi,” to many of these ruins. These ancients occupied thousands of settlements, extensive or miniscule, in the high desert, many remnants of which are surprisingly well-preserved in the intensely dry climate.

The majority are cliff dwellings but a great number are freestanding buildings sometimes of three or four stories, all constructed from the local bedrock. Many clues seem to point to the fact that they were abandoned with stunning suddenness.

To enter a dilapidated dwelling in one of the crumbling ruins with a guide or on an unaccompanied hike and find household goods such as smashed pottery, broken corn grinders, and even remnants of last meals is to be confronted with a situation suggesting very sudden abandonment coupled with actions intended to prevent any future occupants from making use of the contents.

The Anasazi did not have a written language and only the ruins and the thousands of enigmatic paintings and carvings on rock — known respectively as pictographs and petroglyphs — offer scientific clues to the sudden abandonment.

Timbers of ancient tree trunks incorporated into the ruins indicate that around 1200 A.D. the Southwest was hit by a devastating century-long drought that might have provoked widespread conflict among the pueblos.

Archeological digs in the last 50 years have begun to uncover evidence not only of terrifyingly brutal raids but of cannibalism as well. These discoveries are jarring compared to the politically-correct image of the ancestral people of the Southwest living peaceful, harmonious lives — but as the author of a National Geographic article on the Anasazi wrote some years ago, the ancient people did not live their lives for the approval of 21st-Century sensibilities.

And yet in some quarters — particularly among the Navajo people — the very word “Anasazi” has come to be politically charged. A term with Navajo origin, it is said that it can be translated as either “ancient ancestors” or “ancient enemy.”

The latter rendering offers support to the oral traditions among some pueblo people that the predecessors of the Navajo descending from their ancient home in Canada drove them from their homes and villages.

But the actual events are far in the past and archeological evidence is ambiguous. In any event, whatever the cause of the sudden and mysterious migration, the inhabitants of the prehistoric stone dwellings seem to have fled mainly to the south of their traditional homelands to become the ancestors of today’s pueblo people.

Puye Cliff Dwellings

One of the more impressive abandoned ancient sites lies an hour’s drive northwest of Santa Fe, New Mexico, and is known as the Puye Cliff Dwellings which the people of the modern Santa Clara Pueblo identify as their ancestral home.

Pronounced “POO-yay,” the ruins are situated on a lofty mesa just east of a gigantic volcanic crater known as the Valles Caldera that resulted from a devastating eruption around 1.2 million years ago. The eruption formed vast layered beds of soft rock known as pumice and tufa as well as the black volcanic glass obsidian, which have eroded into hills and mesas.

The softness of the pumice and tufa made it easy to carve shallow caves and stairways into the strata while the obsidian could be worked into knives, spear points, and arrowheads.

In addition, the base of the cliffs and the top of the mesa were deeply littered with shattered angular rocks that could be stacked into walls and mortared with mud to produce free-standing single- or two-story dwellings or used to line the partially-underground sacred spaces called kivas. Their geometric shapes and the shadows that fall on them in the harsh desert sunlight create a curiously contemporary look suggestive of cubist and minimalist art.

The top of the mesa is littered with fragments of pottery from different eras, many of them showing complex, colorful designs, as well as flakes of obsidian left from cleaving arrowheads and knives from larger chunks of the rock. Since these materials were used by their ancient forebears, modern pueblo people regard them as worthy of respect and visitors are urged not to remove them.

But contemporary pueblos have different explanations for why the fragments are there. Some claim that, since they came from the earth in the first place, the respectful thing is to allow them to return to the ground, while others will insist that the ancient inhabitants smashed their household items upon deserting their ancestral homes to prevent invaders from making use of them, just as many archeologists have argued.

Native American guides at Puye tell visitors that the ancient builders chose the location because its steep surrounding cliffs made it easily defensible, a site that would be abandoned only under great pressure — seeming to support the latter interpretation of the ubiquitous fragments.

Puye today is a barren place — parched, and exposed to the unforgiving New Mexican sun. As with many other ancient sites in the Southwest, the nearest water source is a small stream at some distance from the base of the mesa.

The thought of the women of Puye hauling water in jugs up steep steps and ladders to reach the top while the men trudged into the far green hills of the caldera in search of game rapidly destroys any romantic notion of the lives these people led, which from all archeological evidence was, as the cliché goes, “brutish and short.”

And yet, the stark elegance of the ruins and the intricate designs on the pottery fragments speak of a creative sensibility that even the harshness of daily life in Puye could not squelch.

Acoma Pueblo

An hour’s drive west of the city of Albuquerque on Route 40 is Acoma, another pueblo with an ancient history. Where the side road leading to it departs from Route 40, it first passes clusters of modern houses with air-conditioning units and satellite TV dishes — signs of the affluence brought to the contemporary Acoman people by the presence of a casino.

The road next traverses miles of evocative New Mexican scenery: steep, rolling, sandy hills fragrant with wild sage, dotted with junipers, pinyon pines, and the beautiful but poisonous datura; but it then passes into an almost unearthly world of jagged buttes, pinnacles, and mesas eroded from great strata of red and tan sandstone deriving their tints from oxides of iron.

Acoma Pueblo — known as “Sky City” — emerges slowly from the landscape, first appearing to be a scattering of enormous cubical and rectangular blocks of the sandstone scattered across the top of a mesa above precipitous cliffs. Closer, the blocks acquire tiny windows and what appear to be spindly ladders climbing to smaller blocks perched atop larger ones.

From the Acoma Visitor Center, a modern paved road ascends the mesa in a series of broad curves.  Unlike Puye and the thousands of other prehistoric sites scattered across the Southwest, Acoma Pueblo is still occupied.

The people of Acoma have a long history that begins — as with the stories of so many of the pueblos — in times cloaked in legend and mystery. East of the mesa on which Acoma sits is another rocky citadel known as “Haika” and, according to tribal legend, it is the ancestral home of the people of Acoma.  Regarded as sacred, Haika is off-limits to everyone, including — and perhaps especially — to archeologists and hikers.

At some point in the past, according to oral tradition, the Acomans left their legendary ancient home for reasons mysterious and moved to their present home in the sky on which they have dwelt for at least 1,000 years. There followed times of both peace and turmoil, climaxing in the revolt against their Spanish conquerors known as the Pueblo Rebellion.

Incensed by the Spaniards’ enslavement of their people and by forced conversion to Catholicism, the people of Acoma and other pueblos rose up and drove the Spaniards from their lands. And yet — paradoxically — the proud Acomans and the citizens of many modern-day pueblos are intensely religious, mixing fervent Catholicism with elements of their traditional religions in ways that — like Haika — are off-limits and mysterious to non-pueblo people often known collectively as “Anglos.”

The beautiful church dedicated to Saint Estaban (Saint Steven) is proudly displayed as the spiritual center of Acoma Pueblo. The church is constructed of the local sandstone and mortar, is fitted with wooden supports and railings carried from many miles away, and is covered in adobe formed from mud mixed with wild grasses; hence, it echoes the Biblical “bricks with straw” of the captive Hebrews in Egypt.

Acoma has been famous for centuries for its intricately-decorated, thin-walled pottery that is still sold by individual craftspeople and in the galleries of Santa Fe. The pottery is molded from a deposit of clay reputed to be over five miles from Acoma, and, like the artisans of all of the pueblos, these artisans keep the sources of the clays carefully guarded secrets.

A large sampling of traditional Acoman pieces is displayed in a museum in the pueblo’s visitors’ center. From there, guided tours ascend the mesa, with travelers riding in air-conditioned vans that seem to move through time as well as space, for atop the mesa the traditional dwellings have changed little over a thousand years and give a clear idea of what the great citadels of Mesa Verde, Chaco Canyon, and Canyon de Chelly must have looked like before their sudden abandonment.

The adobe dwellings climb to two or three stories, accessed by sturdy ladders joined at their tops by beams carved to evoke thunderbolts symbolically.

Some of the individual houses of “Sky City” are hundreds of years old, and none have electricity, central heating, air-conditioning, or indoor plumbing. Several shallow reservoirs carved into the largely impermeable sandstone were used by the ancient occupants to hold rainwater and snowmelt.

However, concessions to basic necessities have been made: vans transport water for drinking, cooking, and washing to the inhabitants, space heaters and wood stoves provide heat for cooking and warmth, and a series of porta-potties are maintained by the pueblo.

The thick adobe-covered walls of the residences hold in heat in winter and keep the interiors relatively cool in the sometimes fierce summer heat — and then, the high elevation of the pueblo frequently provides a cooling breeze. But in other ways those Acomans who have not left the mesa for modern comforts — numbering today only about 15 — are indeed living the ways of their ancient predecessors. 

On the other hand, on the occasion of major religious feasts and tribal celebrations, hundreds of Acoman people return to their ancestral homes on the mesa and also live for a time as their ancestors lived and keep alive tribal traditions.

Unlike the guides at Puye who readily assert that the mesa top was selected for purposes of defense, docents at Acoma explain that their high mesa was chosen because it brought the inhabitants above the rugged surroundings and closer to the sky and to the stars that were such a source of wonder and mystery to the ancient people.

Perhaps both explanations are correct. The view from “Sky City” reveals an ancient landscape sculpted from thick strata of colorful sandstone eroded into bewitching shapes by the agents of water, wind, and ice, the subject of many tribal stories that are closely guarded from “Anglos.”

But the proud people of Acoma are happy to share much of their heritage with the outside world during times of major feasts and celebrations.

Acoma on Christmas Eve is legendary throughout central and northern New Mexico. Hundreds of the pueblo people gather on the mesa for midnight Mass at St. Estaban and for visits with friends and family — and the night echoes with ancient songs.

Then the road ascending to the top of the mesa and the roofs of family dwellings are lit with many thousands of “farolitos,” the iconic Southwestern Christmas decorations made from small paper bags lit by candles within, and the twinkling lights of the farolitos mingle with the stars in the clear New Mexican night.

And then, even Anglos understand why Acoma is called “Sky City.”

Location:

— Photo by Mike Nardacci

The Onesquethaw Creek south of Clarksville emerges from the woods and flows for a time along Lower Flat Rock Road, exposing its strange topographic features to easy viewing.

— Photo by Mike Nardacci

Erosion and chemical solution have formed a series of descending terraces, some partially blocked by vegetation. Water flows over, through, and around these terraces to create a confusing maze.

— Photo by Mike Nardacci

Becraft Limestone contains massive quantities of fossilized fragments of ancient shellfish called brachiopods, visible as crescents or rings. A pair of sunglasses is included for scale.

— Photo by Mike Nardacci

Close-up of a section of the streambed showing the confusing maze and some temporarily isolated potholes providing mini-environments for minnows, pollywogs, and water bugs.

— Photo by Mike Nardacci

The Onesquethaw continues its southward flow through channels and potholes in the Becraft Limestone, eventually to join up with the Coeymans Creek before entering the Hudson River.

The stream called “Onesquethaw” undergoes extensive changes as it flows from its placid source in our portion of the Appalachian Plateau known locally as “the Helderbergs.” It incises its way through several rock layers — or “strata” — from the Devonian Period, which are between 360 and 400 million years old.

It has formed canyons, flows lazily over stretches of level terrain, and gurgles over gentle rapids and through potholes. Eventually it joins with Coeymans Creek before discharging into the Hudson River where its waters mix with those of thousands of other tributaries on the river’s course toward the Atlantic Ocean.

Some of the Onesquethaw’s most rugged and picturesque segments are off limits to most hikers as it flows through private lands; however, a stretch that parallels Lower Flat Rock Road off the section of Route 443 known as the Delaware Turnpike is easily accessible by car or bike and provides a quiet place to reflect on our area’s almost unimaginably long geologic history and the thoughts that changing seasons bring.

Privately-owned Helderberg Lake lies just north of Route 443 where it briefly runs congruent with Route 85. The lake was enlarged by an artificial dam in the 1930s and at its southern end its overflow becomes the Onesquethaw Creek as it cascades down a series of terraces and has carved out a steep gorge that descends for a mile or so as it plunges out of the steep hills of the town of Berne.

Almost entirely on parcels of private property, the gorge is formed from the thin-bedded Hamilton rock layers, strata composed of dark sandstones and shales. About 220 million years ago, a vast landmass that was to become Europe was beginning collision with proto-North America in one of the great movements known as plate tectonics.

The collision was closing the body of water that had divided the two landmasses and was pushing up a towering range of mountains in what is today eastern New England. Rain and snowmelt washed millions of tons of sediments from the slopes of these ancient mountains, filling in the waterway between the land masses and forming a series of interlocking deposits termed by geologists “the Catskill Delta.”

The deposits eventually turned to rock and are visible in western Albany County and throughout the extensive eroded plateau known as the Catskill Mountains.

This material alternates between being moderately resistant to stream erosion and poorly resistant, and thus the gorge below Helderberg Lake frequently exhibits a profile similar to that seen in many canyons in the West such as the Grand Canyon: a series of alternating steep and gradual slopes covered with piles of enormous quantities of eroded fragments called “talus.”

Near the area where Wolf Hill Road, Route 85, and Route 443 intersect, the Onesquethaw has cut down through the sandstone and shale layers to the Onondaga Limestone, the highest stratum of limestone in Albany County. The Onondaga is a hard, clean gray stone, indicative of its formation during the Devonian Period in clear, shallow, warm waters.

It is rich with fossils of many kinds of corals and in places features nodules and beds of chert, a dense rock commonly known as flint composed of silica. A number of extensive Albany County caves have formed in this layer.

For the next couple of miles, the stream runs parallel to Route 443 over nearly flat terrain with a surface bedrock of the Onondaga which in this stretch is highly fractured. In dry times of the year, the stream may flow entirely under the exposed streambed leaving it bleached and dry. In periods of heavy storms and snowmelt, the Onesquethaw boils to the surface and, gathering temporary energy from the flood pulse, may create whirlpools and rapids as it flows south toward Clarksville.

But approaching the hamlet, the stream’s path is temporarily diverted east by imposing Bennett Hill, a glacially-sculpted “rock drumlin” composed of the Hamilton strata. Eroded by the mile-high glacier that passed over it thousands of years ago, the step-like terraces of Bennett Hill are visible for many miles.

The Onesquethaw again becomes somewhat energized as it cuts through the limestone at the base of Bennett Hill and flows down through another impressive canyon. Here the stream encounters an extensive series of faults whose “slickensides” — tell-tale parallel grooves carved into the bedrock during an earthquake — are visible in sections of the canyon walls and the streambed, and in places the strata are bent and contorted by the movement of the ancient fault.

Within the canyon are small caves and springs, plunge pools, enormous potholes, giant boulders and slabs detached from the bedrock, and thick deposits of sediments composed of many rock types, some carried down from the Helderbergs, others left behind long ago by the retreating glaciers.

But in this stretch, the Onesquethaw is described as an “underfit” stream, meaning that with its average velocity — which for most of the year in these modern times is not much more than a trickle — it is incapable of eroding great chunks of the canyon’s hard bedrock or transporting and polishing large boulders. Much of this erosion occurred at the end of the glacial period when the Onesquethaw may have carried hundreds of times its present-day volume due to the melting of the glaciers.

As the Onesquethaw approaches the eastern boundary of the village, it cuts down into the crumbly Esopus Shale and for a stretch of several hundred feet it has exposed the marvelous fossils characteristic of the Esopus known commonly as “rooster tails.” These fossils represent a vast colony of tube worms whose feeding tunnels radiate out from a single point.

They indicate an ancient environment of relatively deep, calm water in which the delicate worms could have remained anchored to a single point on the sea bottom for a lifetime and burrowed through the murky organics-laden mud absorbing nutrients.

Just beyond the rustic stone bridge over the Onesquethaw on Tarrytown Road there is a pull-off on the left side of the road where a short path leads to the stream’s edge and offers a dramatic view of strata contorted by the movement of an ancient fault.

Beyond this point, the Onesquethaw is not visible from any public road and flows through private land. It continues to cut downward through the Esopus Shale and cascades over an impressive waterfall into a plunge pool.

It finally incises its way through the entire exposure of the Esopus and comes into contact with an even older Devonian layer known as the Becraft Limestone. But it is not until the stream bends and enters the wide, shallow valley through which passes Lower Flat Rock that it again becomes easily accessible and enters one of its most evocative sections.

Here for a thousand feet or so paralleling the road the Onesquethaw flows due south and is bordered on both sides by a forest of hemlocks and pines, floored by ferns, mosses, and other vegetation that flourishes in humid, shady environments. The stream itself broadens out and descends a series of low terraces producing miniature rapids as it continues through a bewildering maze of gurgling and babbling channels, potholes, and plunge pools.

The Becraft limestone layer has a thickness of only about 20 feet in this part of the county, but along Lower Flat Rock Road the rock has been smoothed off by the passage of the ancient glaciers in a broad plain known to geologists as a “bench.” Although much of the bedrock is covered here by a thin layer of soil and the forest it supports, the Onesquethaw’s path reveals the Becraft with its fascinating collection of fossils and erosional features.

The Becraft is a very hard rock and, because its surface was subjected first to abrasion by the glaciers and subsequently polished naturally over centuries by tiny water-borne sediments acting like fine sandpaper, exposures show the clean, gray limestone is flecked with thousands of closely-packed fossils. Mainly these are the shells of sea creatures known as brachiopods and they stand out as shiny white circles or crescents.

The Becraft resembles a rock type called “coquina,” which consists of great masses of fragments of sea shells naturally cemented together by calcium carbonate and often found near reefs and on the coast of Florida and islands in the Caribbean Sea. That most of the shells have been shattered indicates that the rock formed millions of years ago in relatively shallow-water environments in which the shells were subjected to violent agitation and deposition by waves in Devonian seas.

In addition, the Becraft in the streambed shows many fractures and joints — cracks caused by repeated freezing and thawing over centuries as well as expansion of the bedrock as upper layers are removed by erosion.

Because the limestone and its fossils are made of calcium carbonate, the rock is subject to chemical weathering by mild natural solvents such as carbonic acid, formed when water absorbs carbon dioxide as it falls through the atmosphere or flows over rotting duff on the forest floor.

As a result, the mildly acidic Onesquethaw waters have worked their way through every crack and crevice in the streambed, dissolving the maze of channels and potholes visible along Lower Flat Rock Road. Small channels encounter larger ones, fractures lead into potholes and plunge pools, and the tiny distributaries enter a confusing pattern of flow, sometimes briefly backwards or sideways or in miniature whirlpools, but eventually forward toward the Hudson under the pull of gravity.

Tiny dams formed by the presence of water-loving plants or water-borne debris create miniature pools of slow-moving or still water in which minnows and pollywogs and water bugs find refuge, feeding on tiny prey or bits of organic matter carried by the stream.

And of course, the patterns of flow and the sounds they produce change with the seasons and the weather.   Snowmelt and seasonal rainstorms raise the volume of the stream, causing the channels to overflow and create earnest-sounding if temporary rapids.

In dry times — especially late summer and fall — low flow in the Onesquethaw reduces the sounds of the stream to whispers. In winter, thick layers of ice form on the bedrock beneath the overhanging boughs of hemlock, creating weirdly-sculpted shapes in the streambed as well as yet more channels and dams, and water may burst from them like the icy rivers that emerge from the base of glaciers.

At such times, the stream appears black and lifeless and the sounds of fracturing and shifting ice may shatter the quiet of the valley. But with spring will come again the agreeable babbling of the brook and the cries of peepers.

A professor of mine once told our class that to be an effective geologist, one must have a good imagination — and this portion of Lower Flat Rock Road is an excellent stimulant to the mind.

Standing on its banks, one can imagine the crash of ancient seas transporting and depositing sediments and sea shells, the growth and grinding of glaciers during the Great Ice Age, and the relentless shaping and reshaping of the landscape and the labyrinths of the streambed as the Onesquethaw continues its unrelenting search for the sea.

Location:

The Enterprise — Mike Nardacci

Clarksville Cave is one of the most heavily-visited non-commercial caves in the Northeast; this is one of its historic entrances.

The Enterprise — Mike Nardacci

The entrance to Onesquethaw Cave is flooded. The cave lies in a low area and is subject to high water in times of heavy precipitation or snowmelt.

The Enterprise — Mike Nardacci

The rustic cabin in the Schoharie Caverns Nature Preserve is frequently used by college outdoor clubs and geology classes on field trips.

The Enterprise — Mike Nardacci

Situated at the base of a limestone cliff, the entrance to Schoharie Caverns leads to a high canyon passage richly decorated with calcite formations.

— Photo by Art Palmer

Knox Cave in winter has massive ice deposits cloaking its entrance. The photo was taken around 1960 when the staircase was still intact, but the scene looks much the same in any Helderberg winter.

— Photo by Mike Nardacci

The picturesque entrance to Spider Cave gives no hint of its uninviting interior though its name alludes to the creatures that populate its walls in great numbers.

 

The precise locations of the caves referred to in this column have been left deliberately vague to protect both the caves and inexperienced persons who might wish to enter them. Those interested in local cave exploration are urged to check out the website of the Northeastern Cave Conservancy — www.necaveconservancy.org — and to consider a cave trip tailored to their abilities during the period between May 1 and Sept. 30 when the caves are open to visitors.

One might — in a whimsical moment — regard it as “The Spelean Archipelago.”

Though sport — and scientific — cavers have long frowned upon the term “spelunker,” the noun “speleology” — the scientific name for the study of caves, derived from “spelaion,” the Greek word for a cave — and the adjective “speleological” have long been standard usage.

Across the United States, preserves in karst areas dot the map, ranging in size from a single acre to hundreds — karst” being the term for a region of limestone or marble bedrock containing caves. In our part of the country they are owned and/or managed by two organizations: the Northeastern Cave Conservancy, which recently celebrated its 40th anniversary, the website of which declares that its mission is the conservation, study, acquisition, and management of northeastern caves; and the National Speleological Society, today an international, organization of sport and scientific cave explorers.

The organizations are commonly referred to respectively as “the NCC” and “the NSS.” Their preserves protect numerous caves, the watersheds they involve, the unique life within them, and the classic karst surface features such as sinkholes, disappearing streams, and springs. Many local cavers are members of both organizations, the websites of which detail the history and geology of the various preserves.

From Oct. 1 to the end of April, many Northeastern caves — and all of those under the ownership or management of the NCC and the NSS — are closed to protect the caves’ bat populations, which in recent years have been ravaged by the insidious disease known as White Nose Syndrome.

Commercial caves such as Howe Caverns and a number of privately-owned caves that do not harbor bats remain open; however, winter has never been a very popular time for sport caving except for the most dedicated, given the fact that Northeast caves are almost by definition very wet, and slogging through snow in subfreezing temperatures to and from the caves can be extraordinarily miserable.

The National Speleological Society was founded in 1941 by a small but dedicated group of cave explorers and since has grown to an international organization with thousands of members. In the Northeast, the NSS owns three Schoharie County cave preserves: the Schoharie Caverns Nature Preserve; the James Gage Karst Preserve; and McFails cave, the most extensive in the Northeast. All three properties were donated to the NSS by generous patrons and have been maintained over the years by dedicated volunteers.

Knox Cave tragedy leads to stewardship

Yet the NCC was born as the final result of a tragic caving accident in 1975.

In May of that year, several college students from Albany were attempting to enter Knox Cave, which even late in the season still had a huge mass of ice encrusting the part of its sinkhole above the entrance.

The cave near the hamlet of Knox had sporadically been run as a commercial operation like Howe and Secret Caverns in Cobleskill, most famously under the ownership of Delevan C. Robinson and his wife, Ada. In the mid-20th Century, the couple were responsible for the building of an elaborate staircase offering access to the cave, which lies over 100 feet underground, and for constructing walkways and installing lighting for tourists.

D.C. seems to have had what the Irish call “the gift of blarney”: Some of his descriptions of the cave and its extent were — to put it gently — fanciful. But the cave features both large, easily-accessed passageways and more challenging sections that require stamina and sometimes ropework of explorers and it has attracted serious cavers for many generations as well as tourists during the relatively brief periods when it was commercialized.

The Robinsons also built a large roller rink adjacent to the cave’s entrance sinkhole that for a while, in the 1940s and 1950s, was the scene of skating parties and country dances. It seems to have formed a center of social life for the Hilltowns in the days when not many hardworking Helderberg folks could afford the time or the money to travel to nearby cities for entertainment.

But following D.C.’s death, commercial operation of the cave ended for the last time in 1961, though sport cavers and scientists continued to gain access to Knox with the kind permission of D.C.’s widow, Ada, until she died in 1964.

Some time in the mid-1960s, the largely abandoned property was purchased by a Long Island corporation called “Organa Industries,” which announced its intention to restore the cave and dig out a boulder-choked sinkhole adjacent to its classic entrance to allow a through trip. But Organa Industries went belly-up and the restorations never took place.

Old-timers in the Knox area may remember the huge steam shovel that stood for years in the field next to the commercial entrance but it seems never to have been employed in digging the clogged sinkhole and it eventually collapsed into a rusty pile of warped metal and cables.

The result was that access to Knox Cave was without any sort of control; in the years that followed, the staircase and the walkways deteriorated and the lighting system and many of the cave’s natural decorations were vandalized, and the skating rink and the Robinsons’ 200-year-old farmhouse were torched.

Even the massive frozen waterfalls that formed in winter from drainage in the fields around the Knox sinkhole did not deter visitors from entering the cave. Sometimes the warmer (48-degree) air within the cave would melt a tight hole allowing access to the adventurous — or risk-takers — while at other times the even more foolhardy were rumored to be using sledge hammers to smash their way through the ice to gain entrance.

In any case, one day in May 1975, as a group of Albany students tried to enter the cave through its ice-encrusted entrance, spring runoff from surrounding fields poured in a cascade behind the ice deposits.  The result was that a massive block of ice broke away and came crashing down, killing one student and leaving another paralyzed from the neck down.

By that time, the cave and surrounding land had been sold for non-payment of taxes to a doctor from Schenectady. Fearing additional injuries and lawsuits, the doctor attempted to donate the cave to the National Speleological Society. But the same fears caused the NSS to reject the offer, and a group of cavers became concerned that the cave might be acquired by someone who would ban all exploration or even bulldoze its entrance sinkhole effectively closing it permanently.

Thus, in 1978, three area men — Robert Addis, Dr. Art Palmer, and Jim Harbison — formed the Northeastern Cave Conservancy as a not-for-profit group and Knox Cave has continued to be made available to qualified cavers.

Over the years, subsequent exploration has added close to 1,000 feet of previously unknown passage to the map of Knox Cave and revealed another segment of passage yet to be connected to Knox known as Crossbones Cave. And, over the years, through purchase or donation, the NSS and the NCC have acquired a number of other parcels of land containing caves that are also well-known to explorers.

Caves galore

A western portion of the Helderberg Plateau known as Barton Hill in Schoharie County rises steeply above the Fox and Schoharie creeks. A standing joke among cavers is that the hill is hollow because of the numerous caves that underlie it.

One large parcel of land owned by the NSS was donated by the Gage family and contains the Schoharie Caverns, which resembles a slot canyon; its entrance lies at the base of a limestone cliff on the edge of the plateau.  Schoharie Caverns consists of nearly half a mile of streamway featuring beautiful stalactites and stalagmites that decades of visits by college outing clubs and other groups have left marvelously intact.

A rather spartan cabin on the property is maintained by local cavers and is available for groups visiting Schoharie Caverns and other nearby cave preserves.

And there are many. The NSS also owns another large parcel of land on Barton Hill known as the James Gage Karst Preserve; it contains Ball’s Cave, named after its 19th-Century landowner.

Its vertical entrance lies in a heavily-wooded section of the hill and has drawn visitors for over 150 years.  The cave features immense rooms as well as low crawl ways, and a diminutive flooded segment of the cave known as the “Lost Passage” requires cavers to experience a chilling “ear dip” to pass through it.  (Do you really want to ask?)

Although there are a number of other known or suspected caves on Barton Hill not under the control of the NSS or the NCC, Spider Cave was recently donated to the NCC by a local landowner. Its alluring entrance has been described as “Storybook,” but explorers have found that it is a very short story except for those with the intrepidity to challenge its agonizingly tight, wet main passage that extends for over a thousand miserable feet into the plateau.

And those who enter its easily accessible first hundred or so feet will encounter scores of its eponymous creepy occupants scampering across the cave’s water-smoothed walls.

McFails is the jewel

Generally considered the “jewel in the crown” of Northeast caves is McFails Cave on the Cobleskill Plateau. Its entrance is in a beautiful hemlock-and-hardwood forest pockmarked with gaping vertical sinkholes, some of which take voluminous quantities of water from time to time.

Only a short and very unpleasant segment of McFails was known until 1961 when some students from Cornell University plunged through a pool with only a few inches of airspace and discovered that the cave did not end at the uninviting pool. Today the cave is known to be over seven miles in length, much of which consists of high canyons and large chambers beautifully decorated with calcite formations.

But the cave can be treacherous: Entrance requires rappelling down 70 feet — in wet weather through a waterfall — and much of a cave trip involves constant immersion in a cold stream, making the wearing of a wetsuit a necessity. The cave has been hydrologically connected to other caves on the plateau, meaning that water in them them has been traced to McFails.

Thus the potential exists for a cave system some 26 miles in length — a fact likely to draw intrepid explorers for years to come.

Clarksville Cave is the best known

Undoubtedly the NCC-owned cave that is best known to the general public is Clarksville Cave, which has drawn visitors for well over 150 years. Groups from camps, schools, churches, and colleges regularly visit the cave between May 1 and Sept. 30.

Clarksville has three known entrances and lies beneath a hardwood forest laced with nature trails. While much of the cave consists of subway-tunnel size passages, more adventurous visitors are drawn to its tight — and wet — challenging sections that lead to pools and a picturesque waterfall.

Despite its easy accessibility and heavy traffic in summer months, much of the cave is relatively pristine and its numerous classic features both above and below ground make it a veritable textbook example of cave and karst geology.

Ominous Onesquethaw

Not far from the village of Clarksville is the lesser-known Onesquethaw Cave also owned by the NCC. Named for the stream that flows through the valley in which its entrance lies, its low, twisting passages are studded with fossils and its sometimes maze-like layout gives the cave a certain allure.

But Onesquethaw is not for the novice cave explorer and has long had a somewhat ominous reputation. It lies in a low area that is prone to flooding and, in times of sudden heavy precipitation, a roaring stream enters the cave and can fill its passages to the ceiling.

In 1991, a group of college students became briefly trapped in Onesquethaw when a torrential surge of water flooded the cave, setting off a massive rescue effort involving the Albany-Schoharie Cave Rescue group and local fire companies as well as news organizations from all over the Northeast.

The students had fortunately found a room with a high ceiling and were able to cling to the walls until the water levels finally dropped and allowed them to leave the cave.

As the students’ experience in Onesquethaw Cave demonstrates — the subterranean world demands respect of those who enter it. The Northeastern Cave Conservancy and the National Speleological Society have not only managed to acquire and keep open many classic Northeastern caves for qualified visitors, the groups have educational and scientific components as well.

Through work with the general public as well as scientists and qualified students, ranging from grade school right up through university-level, the organizations have helped to maintain and protect the resources of the world beneath our feet.

And the NCC and the NSS are not alone. All across the 48 contiguous States and in Alaska and Hawaii, many hundreds of acres of karst lands and areas underlain by lava caves have been acquired and protected by organizations of dedicated cavers — a “spelean archipelago” indeed.

Could statehood be far behind?

Location:

— Photo by Art Palmer

Knox Cave in winter has massive ice deposits cloaking its entrance. The photo was taken around 1960 when the staircase was still intact, but the scene looks much the same in any Helderberg winter.

— Photo by Mike Nardacci

The picturesque entrance to Spider Cave gives no hint of its uninviting interior though its name alludes to the creatures that populate its walls in great numbers.

The precise locations of the caves referred to in this column have been left deliberately vague to protect both the caves and inexperienced persons who might wish to enter them. Those interested in local cave exploration are urged to check out the website of the Northeast Cave Conservancy — www.necaveconservancy.org — and to consider a cave trip tailored to their abilities during the period between May 1 and Sept. 30 when the caves are open for visitors.

One might — in a whimsical moment — regard it as “The Spelean Archipelago.”

Though sport- and scientific-cavers have long frowned upon the term “spelunker,” the noun “speleology” — the scientific name for the study of caves, derived from “spelaion,” the Greek word for a cave — and the adjective “speleological” have long become standard usage.

Across the northeastern United States, preserves in karst areas dot the map, ranging in size from a single acre to hundreds — “karst” being the term for a region of limestone or marble bedrock containing caves.  They are owned and/or managed by two organizations known as the Northeast Cave Conservancy, which recently celebrated its 40th anniversary, and the National Speleological Society — commonly referred to respectively as “the NCC” and “the NSS.”

The preserves protect numerous caves, the watersheds they involve, the unique life within them, and the classic karst surface features such as sinkholes, disappearing streams, and springs. Many local cavers are members of both organizations, the websites of which detail the history and geology of the various preserves.

From May through September, the NCC also offers instructions on access to the caves for the qualified public. From Oct. 1 to the end of April, many Northeastern caves — and all of those under the ownership or management of the NCC and NSS — are closed to protect the caves’ bat populations, which in recent years have been ravaged by the insidious disease known as “White Nose Syndrome,” or “WNS.”

Commercial caves such as Howe Caverns and a number of privately-owned caves that do not harbor bats remain open; however, winter has never been a very popular time for sport caving except for the most dedicated cavers, given the fact that Northeast caves are almost by definition very wet, and slogging through snow in sub-freezing temperatures to and from the caves can be extraordinarily miserable.

The National Speleological Society was founded in 1941 by a small but dedicated group of cave explorers and since has grown to become an international organization with thousands of members. In the Northeast, the NSS owns three Schoharie County cave preserves: Schoharie Caverns, the Gage Preserve, and McFails Cave, the most extensive in the Northeast. All three properties were donated to the NSS by generous patrons and have been maintained over the years by dedicated volunteers.

Knox Cave tragedy leads to stewardship

Yet the NCC was born as the final result of a tragic winter caving accident in 1975.

In March of that year, several students from the State University of New York Outing Club were attempting to enter Knox Cave through its ice-encrusted sinkhole.

The cave near the hamlet of Knox had sporadically been run as a commercial operation like Howe and Secret Caverns in Cobleskill, most famously under the ownership of Delevan C. Robinson and his wife, Ada. In the mid-20th Century, the couple were responsible for the building of an elaborate staircase offering access to the cave, which lies over 100 feet underground, and for constructing walkways and installing lighting for tourists.

D.C. seems to have had what the Irish call “the gift of blarney,” and some of his descriptions of the cave and its extent were — to put it gently — fanciful. But the cave features both large, easily-accessed passageways and more challenging sections that require stamina and sometimes ropework of explorers, and it has attracted serious cavers for many generations as well as tourists during the relatively brief periods when it was commercialized.

The Robinsons also built a large roller rink adjacent to the cave’s entrance sinkhole, which for a while in the 1940s and 1950s was the scene of skating parties and country dances. It seems to have formed a center of social life for the Hilltowns in the days when not many hardworking Helderberg folks could afford the time or the money to travel to nearby cities for entertainment.

But following D.C.’s death in 1961, commercial operation of the cave ended for the last time though sport cavers and scientists continued to gain access to Knox Cave with the kind permission of D.C.’s widow until she died in 1964.

Some time in the mid-1960s, the largely abandoned property was purchased by a Long Island corporation called “Organa Industries,” which announced its intention to restore the cave and dig out a boulder-choked sinkhole adjacent to its classic entrance to allow a through trip.  But Organa Industries went belly-up and the restorations never took place.

Old-timers in the Knox area may remember the huge steam shovel that stood for years in the field next to the commercial entrance but it seems never to have been employed in digging the clogged sinkhole and it eventually collapsed into a rusty pile of warped metal and cables.

The result was that access to Knox Cave was without any sort of control; in the years that followed, the staircase and the walkways deteriorated and the lighting system and many of the cave’s natural decorations were vandalized and the skating rink and the Robinsons’ 200-year-old farmhouse were torched.

Even the massive frozen waterfalls that formed in winter from drainage in the fields around the Knox sinkhole did not deter visitors from entering the cave. Sometimes the warmer (48-degree) air within the cave would melt a tight hole allowing access to the adventurous — or risk-takers — while at other times the even more foolhardy were rumored to be using sledge hammers to smash their way through the ice to gain entrance.

In any case, one day in March, 1975, although snow still covered the ground, the temperature rose to 50 degrees as a group of students from SUNY Albany tried to enter the cave. Runoff from the melting snow poured in a cascade behind the ice deposits and the result was that a massive block of ice broke away and came crashing down, killing one student and leaving another paralyzed from the neck down.

By that time, the cave and surrounding land had been sold for non-payment of taxes to a doctor from Schenectady. Fearing additional injuries and lawsuits, the doctor attempted to donate the cave to the National Speleological Society.

But the same fears caused the NSS to reject the offer and a group of cavers became concerned that the cave might be acquired by someone who would ban all exploration or even bulldoze its entrance sinkhole, effectively closing it permanently.

Thus, in 1978, three area men — Dr. Art Palmer, Robert Addis, and Jim Harbison — formed the Northeast Cave Conservancy as a not-for-profit corporation and Knox Cave has continued to be made available to qualified cavers. Over the years, subsequent exploration has added close to 1,000 feet of previously unknown passage to the map of Knox Cave and revealed another segment of passage yet to be connected to Knox known as Crossbones Cave.

And over the years, through purchase or donation, the Northeast Cave Conservancy has acquired a number of other parcels of land containing caves that are also well-known to explorers.

Caves galore

A western portion of the Helderberg Plateau known as Barton Hill in Schoharie County rises steeply above the Fox and Schoharie creeks. A standing joke among cavers is that the hill is hollow because of the numerous caves that underlie it.

One large parcel of land owned by the NSS was donated by long-time caver and local attorney Jim Gage and contains Schoharie Caverns, which resembles a slot canyon; its entrance lies at the base of a limestone cliff on the edge of the plateau.

Schoharie Caverns consists of nearly half-a-mile of streamway featuring beautiful stalactites and stalagmites, which decades of visits by college outing clubs and other groups have left marvelously intact.  A spartan cabin on the parcel is maintained by local cavers and is available for groups visiting Schoharie Caverns and other nearby cave preserves.

And there are many. The NSS also owns another large parcel of land on Barton Hill donated by Jim Gage and named in his honor; it contains Ball’s Cave, named after its 19th-Century landowner. Its vertical entrance lies in a heavily-wooded section of the hill and has drawn visitors for over 150 years.

The cave features immense rooms as well as low crawl ways, and a diminutive flooded segment of the cave known as the “Lost Passage” requires cavers to experience an “ear dip” to pass through it. (Do you really want to ask?)

Although there are a number of other known or suspected caves on Barton Hill not under the control of the NSS or NCC, Spider Cave was recently donated to the NCC by a local landowner.  ts alluring entrance has been described as “Storybook,” but explorers have found that it is a very short story except for those intrepid enough to challenge its agonizingly tight, wet main passage that extends for over 1,000 miserable feet into the plateau. And those who enter its easily accessible first hundred-or-so feet will encounter hundreds of its eponymous creepy occupants scampering across the cave’s water-smoothed walls.

McFails is the jewel

Generally considered the “jewel in the crown” of northeast caves is McFails Cave on the Cobleskill Plateau. Its entrance is in a beautiful hemlock and hardwood forest pockmarked with gaping vertical sinkholes, some of which take voluminous quantities of water from time to time.

Only a short and very unpleasant segment of McFails was known until 1961 when some students from Cornell University plunged through a pool with just a few inches of airspace and discovered that the cave did not end at the uninviting pool.

Today the cave is known to be over seven miles in length, much of which consists of high canyons and large chambers beautifully decorated with calcite formations. But the cave can be treacherous: Entrance requires rappelling down seventy feet — in wet weather through a waterfall — and much of a cave trip involves constant immersion in a cold stream, making the wearing of a wetsuit a necessity.

The cave has been hydrologically connected to other caves on the plateau, meaning that water in them them has been traced to McFails. Thus the potential exists for a cave system some 26 miles in length — a fact likely to draw intrepid explorers for years to come.

Clarksville Cave is the best known

Undoubtedly the NCC-owned cave that is best known to the general public is Clarksville Cave, which has drawn visitors for well over 150 years. Groups from camps, schools, churches, and colleges regularly visit the cave between May 1 and Sept. 30.

Clarksville has three known entrances and lies beneath a hardwood forest laced with nature trails. While much of the cave consists of subway-tunnel size passages, more adventurous visitors are drawn to its tight — and wet — challenging sections that lead to pools and a picturesque waterfall.

Despite its easy accessibility and heavy traffic in summer months, much of the cave is relatively pristine and its numerous classic features both above and below ground make it a veritable textbook example of cave and karst geology.

Ominous Onesquethaw

Not far from the village of Clarksville is the lesser-known Onesquethaw Cave also owned by the NCC.  Named for the stream that flows through the valley in which its entrance lies, its low, twisting passages are studded with fossils and its sometimes maze-like layout gives the cave a certain allure.

But Onesquethaw is not for the novice cave explorer and has long had a somewhat ominous reputation.   It lies in a low area that is prone to flooding and in times of sudden heavy precipitation a roaring stream enters the cave and can fill its passages to the ceiling.

In 1991, a group of students from Syracuse University became briefly trapped in Onesquethaw when a torrential surge of water flooded the cave, setting off a massive rescue effort that drew news organizations and cave-rescue teams from all over the Northeast. The students had fortunately found a room with a high ceiling and were able to cling to the walls until the water levels finally dropped and allowed them to leave the cave.

As the students’ experience in Onesquethaw Cave demonstrates, the subterranean world demands respect of those who enter it. The Northeast Cave Conservancy and the National Speleological Society have not only managed to acquire and keep open many classic Northeastern caves for qualified visitors, they have educational and scientific components as well.

Through work with the general public as well as scientists and qualified students, ranging from grade school right up through university-level students, the organizations have helped to maintain and protect the resources of the world beneath our feet.

And the NCC and NSS are not alone. All across the 48 contiguous states and in Hawaii many hundreds of acres of karst lands and areas underlain by lava caves have been acquired and protected by organizations of dedicated cavers: a “spelean archipelago” indeed.

Could statehood be far behind?

Location:

Pages