January 2021

Fire and Ice at Overlook

On the Rocks/Robert Titus

The Woodstock Times

Oct. 14, 1999

The fire tower atop Overlook Mountain is now open to the public, and this is the first autumn that you can legally and safely climb to its top. Sadly, we know that many of you have never even been to the top of Overlook, let alone enjoyed the view from the top of the tower. It’s about time.

The climb to the top is a moderately long one, but it is not all that difficult. There are no cliffs to climb, just a long steady incline. Even if you are not in good shape, you can make the ascent. You will know you have almost gotten there when you see the ruins of the old Overlook Hotel. They’re worth the trip by themselves. Past the hotel, bear right and walk along the edge of the escarpment, the view is grand. Farther along, you reach a substantial topographic shelf right on the mountain edge. This location is favored by campers and is especially busy on nights of the full moon.

Eventually you will want to complete the ascent and go to the fire tower. The tower sits upon a bare, windblown knob of bedrock. The tan sandstones have a venerable history. They were the deposits of the Catskill Delta. We are not entirely sure of the exact origin of these rocks, but many geologists argue that they were the sediments of meandering streams, flowing across the old Catskill Delta. That’s what may have been here. Or maybe not; one is never sure with rocks that are nearly 400 million years old. They are not my real story today, anyway.

The story that we are sure of is about the glaciers that were once here. Right on the trail, just as you make your absolutely final approach to the fire tower, is a very fine example of a glacially polished bedrock surface. The passing ice sanded the rock into its smooth form. Upon that surface are some very fine examples of glacial striations. Striations are long straight scratches that were gouged into the rock as passing glaciers dragged rocks and boulders across the bedrock. Along with the striations are some chatter marks. These crescent-shaped gouges are the products of boulders that sort of skipped across the bedrock as they were being shoved by the moving ice. It must have taken the pressure of a very thick glacier to perform all this damage. A very thick glacier indeed, and that’s where the story gets interesting.

The Overlook striations have a compass direction of south 30 degrees west. We are very familiar with that orientation. We find it at the top of many of the Catskill peaks. This marks the path of the great Wisconsin ice sheet as it passed across the Catskills and advanced toward Long Island, New Jersey and Pennsylvania. This was an enormous sheet of ice, comparable and maybe bigger than the ice sheet of Antarctica itself. If you climb the fire tower, spend a moment contemplating what was once here. The entire landscape all around you was submerged in ice. It is an incredible image, one we never can quite fathom ourselves, even after decades of studying such things.

Just how deep was the ice? Remember those striations, it took the weight of a lot of ice to make them. How thick was it? Well, late at night in geology bars, we argue and debate such things, but we never do come to any final conclusions. Many geologists believe that all of the Catskills were under the ice, others argue that the highest peaks escaped the reach of the glaciers. One thing is for certain however, at least a thousand feet of ice lay above the top of the Overlook fire tower. Look around at the adjacent peaks and then gaze upwards those thousand feet or so and think about all that for a moment. Up there, there once was a great arctic plain, a vast, flat, white waste. Temperatures must have averaged many degrees below zero and winds must have blown snow about constantly. Next, look down to the floor of the Hudson Valley nearly 3,000 feet below. Fill in all this space with ice and then extend it south to Long Island and north to beyond the pole. If you can imagine such a thing, then you are beginning to appreciate just what an event the great ice age was. And it may have happened more than once. We found a second set of striations at a compass direction of west 20 south. It seems glaciers overtopped Overlook at least two times.

Today you would have to go to the south pole to encounter such a landscape. But, if you make yourself a geologist, even just for a day, you can travel to such a landscape today. It’s up there at the top of Overlook and they throw in a fine autumn landscape for free. Many people worked long and hard to open up that tower, go and enjoy it.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.”

Fire and Ice at Overlook

On the Rocks/Robert Titus

The Woodstock Times

Oct. 14, 1999

The fire tower atop Overlook Mountain is now open to the public, and this is the first autumn that you can legally and safely climb to its top. Sadly, we know that many of you have never even been to the top of Overlook, let alone enjoyed the view from the top of the tower. It’s about time.

The climb to the top is a moderately long one, but it is not all that difficult. There are no cliffs to climb, just a long steady incline. Even if you are not in good shape, you can make the ascent. You will know you have almost gotten there when you see the ruins of the old Overlook Hotel. They’re worth the trip by themselves. Past the hotel, bear right and walk along the edge of the escarpment, the view is grand. Farther along, you reach a substantial topographic shelf right on the mountain edge. This location is favored by campers and is especially busy on nights of the full moon.

Eventually you will want to complete the ascent and go to the fire tower. The tower sits upon a bare, windblown knob of bedrock. The tan sandstones have a venerable history. They were the deposits of the Catskill Delta. We are not entirely sure of the exact origin of these rocks, but many geologists argue that they were the sediments of meandering streams, flowing across the old Catskill Delta. That’s what may have been here. Or maybe not; one is never sure with rocks that are nearly 400 million years old. They are not my real story today, anyway.

The story that we are sure of is about the glaciers that were once here. Right on the trail, just as you make your absolutely final approach to the fire tower, is a very fine example of a glacially polished bedrock surface. The passing ice sanded the rock into its smooth form. Upon that surface are some very fine examples of glacial striations. Striations are long straight scratches that were gouged into the rock as passing glaciers dragged rocks and boulders across the bedrock. Along with the striations are some chatter marks. These crescent-shaped gouges are the products of boulders that sort of skipped across the bedrock as they were being shoved by the moving ice. It must have taken the pressure of a very thick glacier to perform all this damage. A very thick glacier indeed, and that’s where the story gets interesting.

The Overlook striations have a compass direction of south 30 degrees west. We are very familiar with that orientation. We find it at the top of many of the Catskill peaks. This marks the path of the great Wisconsin ice sheet as it passed across the Catskills and advanced toward Long Island, New Jersey and Pennsylvania. This was an enormous sheet of ice, comparable and maybe bigger than the ice sheet of Antarctica itself. If you climb the fire tower, spend a moment contemplating what was once here. The entire landscape all around you was submerged in ice. It is an incredible image, one we never can quite fathom ourselves, even after decades of studying such things.

Just how deep was the ice? Remember those striations, it took the weight of a lot of ice to make them. How thick was it? Well, late at night in geology bars, we argue and debate such things, but we never do come to any final conclusions. Many geologists believe that all of the Catskills were under the ice, others argue that the highest peaks escaped the reach of the glaciers. One thing is for certain however, at least a thousand feet of ice lay above the top of the Overlook fire tower. Look around at the adjacent peaks and then gaze upwards those thousand feet or so and think about all that for a moment. Up there, there once was a great arctic plain, a vast, flat, white waste. Temperatures must have averaged many degrees below zero and winds must have blown snow about constantly. Next, look down to the floor of the Hudson Valley nearly 3,000 feet below. Fill in all this space with ice and then extend it south to Long Island and north to beyond the pole. If you can imagine such a thing, then you are beginning to appreciate just what an event the great ice age was. And it may have happened more than once. We found a second set of striations at a compass direction of west 20 south. It seems glaciers overtopped Overlook at least two times.

Today you would have to go to the south pole to encounter such a landscape. But, if you make yourself a geologist, even just for a day, you can travel to such a landscape today. It’s up there at the top of Overlook and they throw in a fine autumn landscape for free. Many people worked long and hard to open up that tower, go and enjoy it.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.”

A Reckless Youth Spent at the Artist’s Grotto

On the Rocks – The Woodstock Times

Aug. 26, 1999

Updated by Robert and Johanna Titus

Late summer is a hard and stressful time of the year for many of the plants and animals out there. That’s the time when the streams run dry. It’s hot in August and the evaporation rate is high, but also the trees are thirsty, and they have been drawing a very large amount of water out of the ground. The results are predictable, first the soils dry up and then the streams follow. We understand the hardships that a lack of water places on the ecosystems around us, but that’s Nature’s way and Nature is cruel. Fortunately, all creatures have evolved in this setting and they are adapted to all this; they will suffer but they will survive.

It is, however, not such a bad time to be a geologist. We are able to go and see many things that are normally under water. It’s easy, for example, for us to hop around on the dry boulders and work our way up a stream. The channel deposits and the bedrock along the banks of the streams are all well exposed, and that is a real treat for a geologist, and we always try to take advantage of it.

Lot’s of other people too. You will currently see large weekend crowds in some of the bigger Catskill creeks. The people are taking advantage of the remaining swimming holes and they are also simply enjoying the easy hiking. And so it is that this is a very good time of the year to go and visit the lower stretches of Kaaterskill Clove, a location called “Artists Grotto.” We are talking about that part of the stream that lies just between the two Rte. 23A bridges that cross the river just above Palenville and just below Fawn’s Leap. Kaaterskill Clove is a spectacular canyon cut into the Catskill Front, but this part is in many ways the best. The river has literally sliced into the mountains here and cut a deep slash, a canyon within a canyon, and it is so nice to visit now.

The geological story of this canyon started right after the last glaciation. Back then a great heap of sediment was carried out of the mountains and dumped in this lower stretch of the clove. If you look at that bit of canyon just downstream from the upper bridge, you will see what is left of that sediment. It’s a heap of course grained, very red sediment. There are lots of boulders, cobbles, and gravel mixed in with plenty of red sand. After this material had been deposited, Kaaterskill Creek went to work eroding it away. The river sliced quickly and easily into this soft stuff and began the carving of our pretty little canyon. As the river cut through this sediment, it found that the bedrock beneath was not much harder. These are mostly soft red shales, and they don’t put up much of a fight against any erosive river.

That’s what made the best of our little ravine. The shale is just hard enough to create perfectly vertical cliffs as the river cuts through it. But it is also soft enough to allow for a rapid down cutting erosion. That’s why this part of the canyon is very narrow and very vertical. There are also a few thick sandstones along this stretch, and they affect the landscape very differently. Sandstone is sturdy stuff, and it holds up well against the erosion of the stream waters. The sandstones form big and little waterfalls. Typically, there are good swimming holes associated with the sandstones and so people love these sites. They swim in the pools and then climb on the rocks to bask in the sun.

All this is typical of a stream which has not been around all that long a time and that is the case with Kaaterskill Creek. It’s sometimes referred to as a “youthful stream.” It began to carve its way into the mountain only during the ice age and that is not very long ago maybe only 120,000 years old or so. That makes it a baby among rivers. The Hudson, for example, goes back many tens of millions of years. Unlike Kaaterskill Creek, the old Hudson has outgrown its wild youth. You will find no deep, vertical canyons in the Hudson. There are no waterfalls or even rapids along the older river, it is too mature for such feckless activities.

The two streams provide us with different sorts of natural beauties: Kaaterskill Creek provides us with a special wild and powerful sort of nature, one which the old Hudson River School artists called “sublime.” The Hudson gives a quiet and serene landscape, the old artists might have called it “picturesque.”

Either way, the artists won.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.”

Regression to the Mean

On the Rocks –

The Woodstock Times, June 17, 1999

Updated by Robert and Johanna Titus 

We live in a world where we are used to the idea of rising sea levels. During hurricane seasons, we expect to see the rising of the ocean’s waters and the flooding of coastal landscapes. We may not be comfortable with the idea of coastal erosion, but we do see it as the “norm.”

Few of us would recognize it, but this is a bias. We are comfortable with the notion of rising sea levels not because that actually is the norm but because we live in a world where the climate has been warming up ever since the end of the ice age. As the climate has warmed glaciers have melted, and meltwater has poured into the seas raising their levels worldwide.

There is, however, nothing actually inevitable about rising sea levels; it could be the other way around. Suppose that the climate was cooling down. Then ice would be forming, water would be withdrawn from the sea to make the ice and the sea levels of the world would be dropping. Throughout the length of Earth history, it must be that there have been as many times of dropping sea level as there were risings. Neither is favored over the long term.

A rising sea level is often called a transgression while a falling sea level is called a regression. Transgressing seas do leave coastal regions susceptible to storm flooding and damage. Such coasts are prone to erosion and, in fact, do erode away.

Regressive coasts are quite different; as the sea levels drop rivers bring sand and mud into the seas and pile them up. The coasts advance seaward. We call that progradation.

You and I are not likely to ever see a good regression, not unless there is a dramatic shift in the climate. So, we will never see a whole coastline prograding. But we can go back in time to eras when the seas were retreating and see the results in the rocks. From Woodstock, travel east on the Glasco Pike to Mt. Marion. There, where Plattekill Creek crosses the road, you will see a towering outcrop. It is mostly black shale. The rock was once black mud deposited in relatively deep waters of the Devonian seas, a little less than 400 million years ago.

The black shale is a fine-grained deposit of mud. Mud accumulates in very thin sheets at the bottom of a quiet sea. The sea was quiet because of the great depths. There were no currents, or tides or waves in the deep water. But look upwards; at the top of the exposure, you will see a number of thick-bedded strata. If you could get up there you would find that these are sandstones. Overall, the outcrop grades from shale to sandstone, from mud to sand. That’s the regressive sequence.

What was happening? At this time the Acadian Mountains, located where the Berkshires are today, were actively rising in a dramatic and important mountain building event called the Acadian Orogeny. As these mountains uplifted, they began to weather and erode. Large masses of rock were converted into even larger volumes of mud, sand and gravel. That’s the fate of weathering rock. Mountain streams transported all of this material as sediment into the adjacent sea. That’s us right here, Woodstock and the whole Hudson Valley region were under water. Marine currents sorted out all of the fine-grained muds and carried them far out to sea where they settled to the bottom as the black muds that hardened into our black shales.

But as mountain building continued gluts of coarse-grained sediment overwhelmed the muds and layers of sand began to pile up Thus, when this sediment hardened, we ended up with the shale to sandstone sequence. That’s a regression.

Go back westward on the Glasco Pike. You will soon encounter other outcrops. These are mostly more sandstones. At the top of the hill, you will even see the cross section of an old river channel. The regression had succeeded, it had transformed a sea into a land area. There should be one of those New York State historical markers up there. It should say “Here the Woodstock area rose out of the sea.” After all, that was an historical event.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.”

A visit to Echo Lake

On the Rocks – The Woodstock Times

June 10, 1999

Updated by Robert and Johanna Titus

The Catskills are rightfully known for their wonderful scenery. Our mountains abound in hidden green cloves with brown and red ledges towering above. Our hiking trails bring us into these secluded natural settings. They have an air of primeval mystery and our park system keeps them that way. Elsewhere around the globe, there are many very different types of mountain landscapes. About as different as you can get are the Alps: there is nothing hidden or secluded about those great peaks. They stand right in the center of Europe with their white mountaintops soaring above the surrounding lands with an in-your-face dominance of the horizons. No one would ever get the Alps mixed up with the Catskills; no one, that is, except a geologist.

Our image of the Catskills of 14,000 years ago has a great deal in common with what we see in the Alps of today. The emblem of today’s Swiss landscape is the Alpine glacier, often called a niche glacier or commonly as a cirque glacier. These form in bowl-shaped mountain depressions, called niches, where snow accumulates, piling up to great depths and hardening into the ice that then begins its flow downhill as a frozen stream. During times of cold climate Alpine glaciers advance into the valleys below; during warmer times they melt back and sometimes even disappear. Not surprisingly, they are very erosive phenomena and have done a lot to shape the Swiss terrains. In fact, we have a word for these special landscapes; we call them “Alpine” landscapes. Similarly, the local glaciers of our ice age did a great deal to form the Catskills as we know them today. If you want to truly understand your Catskill landscapes, you must know something of the Alps!

And that includes, right here in the Woodstock vicinity. Take the red trail almost to the top of Overlook Mountain and then turn north on the blue trail. In about another mile take the yellow trail off to the west. You will soon find yourself descending into one of those mysterious hidden Catskill cloves. At the bottom is a beautiful little pond called Echo Lake. That’s not one of those silly romantic sounding names picked by a housing developer, the lake is very aptly named. Clap your hands or shout abruptly and you will find out why.

Look around you and you will see that Echo Lake is nestled at the bottom of a grand natural amphitheater. Steep slopes rise above on three sides. The only gap is to the southwest, there the lake waters make their escape and flow into the upper Saw Kill. This type of amphitheater is known to geologists as an Alpine niche, a place where once a glacier got organized. We also call such a feature a cirque and it was within the Echo Lake cirque that the Saw Kill glacier accumulated and then began its slow downhill flow. Beyond Echo Lake the Saw Kill glacier flowed at least as far as Cooper Lake and probably much farther.

Cirques are common Alpine landscape features. The steep walls behind the ice are called the headwalls; They were eroded by the ice that was once present. As the ice began its downhill motion, it plucked blocks of rock loose and thus shaped the steep walls. Similarly, the passing ice scoured out the basins of the lakes; in Switzerland such basins are called tarn lakes. Echo Lake is perfectly typical of an Alpine cirque and that is what makes it such a remarkably attractive Alpine landscape feature.

Cirques are common phenomena throughout the Catskills, but we don’t know of any others as well developed as this one. How many others are here and where are they located? That has been a heatedly debated issue ever since the early part of the 20^th Century when they were first recognized. Some geologists have argued that there are very many of them, perhaps scores. Others have argued that there are only a handful and that all the other supposed cirques are nothing more that stream erosion in the upper reaches of our mountains. We think that the Echo Lake cirque is a safe bet. It’s at the top of the Saw Kill glacier which is one of the best known and most widely recognized Alpine glaciers of the Catskills.

It’s a wonderful time of the year to visit Echo Lake, and when you go there please do enjoy our summer scenery. But also pause for a moment and try to imagine the snowy high peaks of Switzerland, for that is exactly what you are seeing here.

   Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.”

Rock Pudding

On the Rocks – The Woodstock Timed

Aug 12, 1999

Updated by Robert and Johanna Titus 

As geologists we are, of course, very fond of rocks. We find the study of bedrock always interesting, often fascinating and occasionally even engrossing. But there are limits; they are, after all, just rocks, and rock is pretty commonplace stuff. But, occasionally, you will round a bend in the trail and be startled by some remarkable bedrock exposure. There are a couple of these on either side of Kaaterskill Clove. When we visit with groups of people, there is almost always someone who cries “whoa” in complete surprise. This remarkable rock is locally called puddingstone.

Go to North Lake State Park and take the blue trail north. That’s the escarpment trail and it is always worth the hike. As you head up the trail you will pass over the ledge at Artist Rock and then cut uphill and away from the escarpment for a bit. Eventually, you will pass left of, and then under a knob of rock called Sunset Rock. It is right there that you first encounter the puddingstone. The puddingstone ledge is up to 20 feet thick. It rises vertically above the trail, so it is quite imposing. But it is the composition of the rock that generates the excitement.

Puddingstone is known, formally, to geologists as conglomerate. That’s a rock composed almost entirely of pebbles. The pebbles are all cemented together, and the effect is to produce a visually stunning lithology. In this case there are a great number of cobbles mixed in with the pebbles so that enhances the visual impact.

But what exactly is a conglomerate? That is, how did this peculiar rock come into existence? The answer to those questions comes slowly with a close examination of the rock. First, notice that most all of these pebbles are nicely rounded. We say that they have been stream washed and rounded by abrasion during a time when they were carried down a river. But where did the stream come from?

Look carefully at the pebbles and cobbles and you will find that they are of all sorts of different types. The largest number are white pebbles of quartz. As you look carefully, you will find a number of other lithologies. Let’s skip a detailed analysis, but it is safe to say that the pebbles are heterogeneous, and they must have come from a place where the bedrock was equally heterogeneous. That was an old mountain range.

The unit of rock is called the Twilight Park Conglomerate. It’s named for a community, across Kaaterskill Clove, where some more nice exposures can be seen. The Twilight Park Conglomerate is part of the Catskill sequence. That’s sediment which washed out of the ancient Acadian Mountains during the Devonian time period. To the east those mountains once towered, perhaps as high as the Andes of today. Like all mountains, they suffered from weathering and erosion and slowly crumbled. During their destruction there were times when unusually large amounts of very coarse-grained material washed out of the mountains, traveling down steep mountain streams, and washing out onto the flat lands below. That’s what happened here.

Look east from Sunset Rock. Imagine blue and purple mountains rising before you. They are white at their peaks. Enormous heaps of brick red coarse sediment lap up onto the flanks of those mountains. Great pounding, roaring, white water mountain streams are cascading out of the mountains and their raging flows continue across those red sediments. The streams flow out onto a large flat delta plain and they slow down as they lose their slopes. It’s then that they lose their ability to transport gravel and they deposit the thick layers of pebbles. These streams wash back and forth and spread the gravel out in thick deposits. Tens of millions of years pass by and the gravels are slowly buried by a thick sequence of more sediment, mostly sand. It all gradually hardens into today’s Catskill sequence.

Those old mountains eroded away entirely, hundreds of millions of years ago. These puddingstones and their pebbles are part of what is left. That, we think, is fascinating.

Contact the authors at randjtitus@prodigy.net Join their facebook page “The Catskill Geologist.