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The art in a weathered old rock

The Catskill Geologists; The Mountain Eagle; Dec. 20, 2019

Robert and Johanna Titus

Often, the hardest part of our writing these columns is shooting the photos. We really need good illustrations of those things that interest us if we are to explain them to you. So, it might not surprise you that, from time to time, we borrow a photo from someone who is better at picture taking than we are, especially if that person is a lot better. Have you ever seen the images done by Art Murphy? Art is a professional photographer and a good friend of ours. We like his work and respect it. He is quite unusual in that he specializes in shooting pictures of fossils. As he lives in the Catskills region, that means he mostly takes photos of Devonian aged fossil invertebrates, and he is good at it. He finds just the right fossil shellfish, catches the perfect light and color, and presto; Art has created art! He runs a blog at “https://artandfossils.wordpress.com.” Every week or so he publishes a series of his recent photos and we always find them fun to view. You might give it a try.

Recently, Art departed from his norm and ran a group of photos which showed not fossils, but the chemical weathering of stratified rocks that was going on in his favorite local quarry. We were inspired to see what we could write about some of his photos and Art generously let us use them. Today’s column shows the first.

Take a look at it; what do you see? We see two colors: a lot of yellow, forming a coating across the surface of this rock and lesser amounts of bluish gray. We think the gray is the rock itself in its natural state. Art showed us around the quarry a few years ago and that’s what we saw. We were, on that day, visiting an ancient sea floor. Those sedimentary rocks had once been sandy muds on the floor of the Devonian Catskill Sea. We saw a lot of fossils in these rocks, so we know it was a sea floor that was favorable to life, specifically there was enough oxygen in the water to support invertebrate animals. But there wasn’t much more than just that. The relatively dark color indicated that there had been some limits on the oxygen contents.

And that was the proverbial rub; these dark sediments hardened to become dark rocks, and both the original sediments and, later the rocks, reflected those limited oxygen contents. Rocks or sediments, it didn’t matter; they had only ever been stable within relatively low oxygen levels – unlike those of the modern quarry floor. Quarrying had brought dark rocks to the surface and exposed them to large amounts of atmospheric oxygen – molecular O_2. That’s when chemical weathering began. The air’s moisture and oxygen “attacked” the iron bearing minerals in the rocks in a chemical process geologists call oxidation. Iron, in the rock, was converted into a mineral that is called limonite, and limonite is the yellow part of Art’s photo

Limonite is an unusual mineral. It does not have a crystalline structure; it might be described as a mishmash of iron, oxygen and hydrogen atoms. Limonite has a common name; it can be called “rust.” When the oxygen of water attacks manmade iron artifacts it is said to rust them away. In this case, the rock will never rust away. Instead, a thin yellow coating will form on the surface of the rock. Oxygen has turned the iron in the rock into limonite. Then it will sit and wait, perhaps years and decades, until just the right artist comes along.

You have learned just a little science today; that wasn’t hard, was it?

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

A bit about us

The Catskill Geologists; The Mountain Eagle, 2017

Robert and Johanna Titus

Are you, like us, a fan of those murder mysteries you see every week on the local PBS station? We watch them all: Miss Fisher’s Murders, Father Brown, Murders in Paradise: you name them; we watch them. Most people have long wondered how it is that those detectives run into murders as often as they do. Every week, like clockwork, somebody is conveniently murdered right under their noses. It would seem that murderers follow them around, doesn’t it?

Well, that part of it does not bother the two of us very much. You see, our lives are a lot like that. No, we don’t have murderers following us around, but wherever we go there is almost always some gem of a geological story – right there in front of us. There has to be; we write these columns week after week.

Think about it the next few days as you go about your routines. You do the same things we do. You drive down the highway and pass by outcroppings of rock. So do we, except that we often stop, get out and take a look. We know that an outcrop might very well have an interesting story to tell. And, with a little luck – presto – we have a column to publish.

You, like us, are likely to find yourself in some substantial Catskills valley. Our landscapes are full of valleys. Well, it is different for us. Almost any valley, here in the Catskills, was likely to have been filled with a glacier back during the Ice Age. And that is where our imaginations kick in. It’s one thing to see a glacier filling some local valley, but we start imagining it at different times of the day and different stages of the Ice Age. Why just look at a glacier when you can see one during a full moon at midnight. We see the moonlight shining down on the ice and creating a shimmering silver glow. We can always wait until the climate warms up and that glacier starts melting. That’s when raging, forming, pounding thundering torrents of meltwater pass by us – or pass beneath us – or – worst of all – over us!

Each of those outcrops offers a different journey into the past. Here in the Catskills, a lot of them are composed of river sandstones. We stand in front of those, hold out our hands and feel the river currents. We see the fish that lived in those streams. We leave those rivers and climb up their banks. Soon we are wandering through forests that lived here in the Catskills about 380 million years ago. These are as real to us as modern streams and forests are to you.

Other bedrock includes limestones. Those almost always take us back to ancient shallow tropical seas. We have been to today’s Florida and the Bahamas, so we know what kinds of places produce limestones. We see grey bedrock, but we experience aqua-colored waters with colorful seaweeds and animal life.

Those television detectives solve their mysteries week after week and so do we. Our explorations take us to ancient landscapes and even older seascapes, but we cannot truly “experience” them until we have done some detective work. We are scientists and we are writing about our science. All scientists have always been puzzle solvers. Our columns are just special types of puzzles. So, come back next week and read our next column. Try to understand that you are following along as two scientists do their work right here in your Catskills.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist” Or read their blog “thecatskillgeologist.com”

A scenic landscape

The Catskill Geologists; The Mountain Eagle; Dec. 12, 2019

Robert and Johanna Titus

Some landscapes are more picturesque than others. Our Catskills are truly blessed when it comes to scenery. For the two of us, however, it can be the geological past that makes a landscape even more remarkable than you might at first think. You travel south on Rte. 145 from Middleburgh and enter Durham. Watch for Stone Bridge Road on the left and turn onto it. You pass an ancient graveyard with fine old stone tombstones and beyond that is a very nice rolling farmland. Do you enjoy walking through such a cemetery, looking at finely made tombstones? Well. this a place for you. But, for us, it was that farm field that caught our eyes. What’s there? Well take a good look at our first photo.

We call this a rolling landscape and that is certainly true. There are so many sinuous curves here; the field gently rolls up and down sort of like the waters of  an old Chinese print of a great stormy sea. There is hardly a geologist anywhere who would not look at this without seeing into its ice age past. We would like you to develop this sort of skill, so, we have a little explaining to do. Those sinuous ups and downs have names. The ups are called kames the downs are called kettles. They formed very late in the Ice Age. At that time this landscape was still thawing out. Many locations had large masses of ice buried in the earth here. How large? Well, many were the size of houses. That’ was a lot of ice in each of these. Most are thought to have been buried in earth. That earth acted as insulation and so each mass of ice took a long period of time to thaw out. Some suggest that the melting took centuries. As the thawing continued, a lot of that overlying earth collapsed upon the melting ice. That resulted in those sinuous kettles. The earth in between was left behind as those sinuous kames. There was more; we drove a short distance down Stone Bridge Road and there was a fine small shallow pool of water. See our second photo. That water fills a particularly deep kettle; it is called a kettle pond.

We are experienced geologists and it took but seconds for us to recognize the big picture here. We saw that we were looking at what is called a glacial moraine. That is a heap of earth that was bulldozed into place by an advancing glacier. That glacier advanced as far as it would– so long as the climate was cooling – bulldozing morainal sediments all along its front. Masses of ice came to be incorporated into these earths. Then the climate warmed up and the ice began its retreat. This new landscape began its thawing out. Those blocks of ice took the longest, but they did melt and that produced those kettles. As the kettles formed so too did the kames.

We stood along the road and looked down the valley and then returned to that ice age past. We viewed a still largely frozen landscape. We saw all those kames and kettles. A few of the kettles still had large masses of dirty ice rising out of them. We craned our necks and looked all the way down the valley as far as we could see. There, in the far distance, we saw a great glacier. It rose high above the valley floor and stretched across the entire valley width. Its front was badly fractured and enormous volumes of meltwater were pouring out of each fracture. This was truly a scenic landscape, perhaps more so to us than to others.

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

Death of a Farm?

The Catskill Geologists; The Mountain Eagle; Dec. 6, 2019

Robert and Johanna Titus

Did you read about Hull-O-Farms in the New York Times recently (Nov. 28, 2019)? The article was on the front page, and it was actually above the fold. That’s something that doesn’t happen to a Greene County farm very often. We were intrigued so we read the article with real interest. Turns out there was some geology in the story so here is our version — above the fold on Page D-1 of the Mountain Eagle!

Hull-O-Farms is a 260-acre farm on Cochrane Road in Durham. It has been farmed by seven generations of the Hull family. That makes it one of the oldest one-family farms in America. Sadly, no member of the eighth generation is able to take over from Frank and Sherry Hull. They have had success running it as a farm-stay bed and breakfast, but they are just getting too old for all the hard-work and they may well have to sell their land for development. There is just a little hope; efforts are underway trying to find young would-be farmers and match them with threatened but available farmlands. But it is doubtful that this will happen. It’s a sad story being repeated all across the country. Family farms are disappearing every day and that was the whole point of the Times story.

But we wondered if there was a geological story behind the story, so we did a little research. The was a brief mention in the Times article that the soils were more than just a bit muddy. We started there. We got out our Greene County soil survey and looked up that stretch of land on its map. We found that most the Hull farmland is blanketed in soils called the Burdett silt loam. And, indeed, they are clay-rich and damp., and they are good for pasturing dairy cattle but the economics of that have become weak. They can be farmed but they are only rated as “moderately suited” for cultivated crops. We wondered why and read on. It turns out that the Burdett soils have been developed upon what is called glacial till. Till is a vaguely defined word in the lexicons of geology but it is, in this case, a thin layer of earth left behind by the melting of a dirty sheet of ice. We called a similar nearby deposit a ground moraine in our July 26^th, column.

Well. this till/ground moraine was developed upon some Devonian aged bedrock which was essentially a shale. So now we had some more researching to do. We got out our copy of the New York State Museum’ geologic map. It looks like Hull-O-Farms lies upon some marine shales called the Manorkill Formation. These shales were deposited as mud on the bottom of the Devonian Catskill Sea about 380 million years ago. Now they are turning back into muds, the muds of the Burdett soils.

So, to sum it all up. The Devonian seas, that were once here, deposited those marine shales. Those rocks sat there for about 380 million years until the Ice Age when glaciers came along. The glaciers gouged out the shales and turned them into the tills that made ground moraines. During the 14,000 years that have passed by since the Ice Age those glacial deposits have been turned into the Burdett soils. The Hulls came along in the late 1700’s and began the farm. Seven generations later that is coming to an end. There is so much history here; the New York Times story missed nearly all of it.

As of Oct. 30, 2024 they are still in business!

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.” Learn more about Hull-O-Farms at www.hull-o.com.

Cold snaps?

The Catskill Geologists; The Mountain Eagle. Nov. 18, 2019

Robert and Johanna Titus

We have seen some pretty cold weather lately. November 12th and 13^th witnessed what was called “historically cold weather.” Forecasters warned that this may be repeated, perhaps many times this winter. Specifically, they predict that cycles of cold Jet Stream air masses will pass slowly across North America during this year’s winter. Each pass is expected to bring similar “cold snaps.” Each cold episode can be an alarming event. How many times have you heard people say, “What happened to climate warming?” That’ a fair question, so we would like to give answering it a try in today’s column. Our argument is that there is, indeed, an explanation for this weather, and it may actually be that has been caused because of, not despite global warming. Obviously, we have a lot of explaining to do.

Let’s begin with a short overview of what the jet stream is. In North America the jet stream is a massive, high-altitude eastward flow of air lying at the boundary the Arctic and the Mid Latitudes. The stream typically undulates up and down through broadly prominent ridges and troughs. See our first illustration. It’s the temperature difference between the cold Arctic and warmer Mid Latitudes that drives the jet stream; the greater the difference, the faster the jet stream. That difference drives the cold troughs and warmer ridges across America. That brings a lot of weather to us, especially as it did in what came to be called “Novembruary.”

                    Normal jet stream, Illustration courtesy of Wikimedia Commons.

In recent decades there has been a consistent and pronounced warming of Arctic realm climates. That’s something we remember that climate scientists predicted at least 30 years ago. At the same time the mid latitudes have only warmed a little, so the differences have been greatly reduced. That has, as would be expected, slowed down the movements of those ridges and troughs. What results is a lot like what happens to auto traffic when it is slowed down. The cars behind catch up with those in front. The ridges and troughs become slower and more closely spaced. But there is more; in order to keep all those air masses moving, both the ridges and troughs must become more expansive. See how, in our second illustration the ridges and troughs are so accentuated. We call this a higher amplitude.

High amplitude jet stream. Courtesy US Geologic Survey

Each trough is a mass of slow moving very cold weather. Just what we saw in middle November. Each trough becomes at least a few days of very cold weather. Each expands far to the south and spreads across a vast expanse of our continent. We all, especially in the south, find this most unsettling. But, as you can see, it’s all a very explainable phenomenon. We think it is something that you should understand.

In the end we are hoping that you will pay more attention to the jet stream part of your local weather forecasts and have a better understanding of what they have to tell.

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

Cold snaps?

The Catskill Geologists; The Mountain Eagle. Nov. 18, 2019

Robert and Johanna Titus

We have seen some pretty cold weather lately. November 12th and 13^th witnessed what was called “historically cold weather.” Forecasters warned that this may be repeated, perhaps many times this winter. Specifically, they predict that cycles of cold Jet Stream air masses will pass slowly across North America during this year’s winter. Each pass is expected to bring similar “cold snaps.” Each cold episode can be an alarming event. How many times have you heard people say, “What happened to climate warming?” That’ a fair question, so we would like to give answering it a try in today’s column. Our argument is that there is, indeed, an explanation for this weather, and it may actually be that it has been caused because of, not despite global warming. Obviously, we have a lot of explaining to do.

Let’s begin with a short overview of what the jet stream is. In North America the jet stream is a massive, high-altitude eastward flow of air lying at the boundary the Arctic and the Mid Latitudes. The stream typically undulates up and down through broadly prominent ridges and troughs. See our first illustration. It’s the temperature difference between the cold Arctic and warmer Mid Latitudes that drives the jet stream; the greater the difference, the faster the jet stream. That difference drives the cold troughs and warmer ridges across America. That brings a lot of weather to us, especially as it did in what came to be called “Novembruary.”

                    Normal jet stream, Illustration courtesy of Wikimedia Commons.

In recent decades there has been a consistent and pronounced warming of Arctic realm climates. That’s something we remember that climate scientists predicted at least 30 years ago. At the same time the mid latitudes have only warmed a little, so the differences have been greatly reduced. That has, as would be expected, slowed down the movements of those ridges and troughs. What results is a lot like what happens to auto traffic when it is slowed down. The cars behind catch up with those in front. The ridges and troughs become slower and more closely spaced. But there is more; in order to keep all those air masses moving, both the ridges and troughs must become more expansive. See how, in our second illustration the ridges and troughs are so accentuated. We call this a higher amplitude.

High amplitude jet stream. Courtesy US Geologic Survey

Each trough is a mass of slow moving very cold weather. Just what we saw in middle November. Each trough becomes at least a few days of very cold weather. Each expands far to the south and spreads across a vast expanse of our continent. We all, especially in the south, find this most unsettling. But, as you can see, it’s all a very explainable phenomenon. We think it is something that you should understand.

In the end we are hoping that you will pay more attention to the jet stream part of your local weather forecasts and have a better understanding of what they have to tell.

Contact the authors at randjtoitus@prodigy.net

“Hurricane Dorian” hits the Catskills?

The Catskill Geologists; The Mountain Eagle; Oct 4, 20

Robert and Johanna Titus                                                                         

Like so many others, the two of us watched with awe, horror and fascination as Hurricane Dorian passed across the Bahamas (2019). We have spent time in the Bahamas, and we know what a low-lying landscape it is. There is so little to stand in the way of such storms. So, as geologists, we know exactly how devastating a powerful hurricane can be in a place like that. Winds of 120 miles per hour swept across lightweight homes, broke them into pieces and swept them away in large numbers. We expected to see that; we feared seeing that and we did see that.

The power of this storm was so great that you might guess that it could leave an imprint in the fossil record, and we are guessing that it did just that. Will Bahamian geologists of the very distant future find a record of Dorian? We think they will. But what about our Catskills geological past: does it present us with evidence of such storms? That’s something the two of us are always on the lookout for, and we would like to tell you about one example that we have found.

Let’s take you down to Rte. 9W in the Town of Glasco.  That’s a little north of Kingston. There you will find a very nice road outcropping which displays something called the Glasco Limestone. The rocks there are stratified. Like almost all limestones, these strata represent the floor of an ancient and shallow tropical sea, much like the Bahamas of today. Each stratum represents a moment in geological time. Some are thicker than others; the thick ones sometimes record more exciting moments.

We found one that was very exciting indeed. Take a look at our photo. It shows a five-inch-thick stratum of the Glasco Limestone which is packed with coarse sediment and fossil shells. Notice how there are so many fossils down at the bottom of the stratum; they are relatively big ones too. Notice too, that as you look upwards, the fossils become fewer and smaller. That tells the story.

Back during the early Devonian time period, about 400 million years ago, this was the bottom of the shallow, tropical Glasco sea. It was approached by and overwhelmed by a powerful storm, perhaps a hurricane. In the space of hours, the currents picked up great masses of shells and sediment, and then carried them in the direction the storm was moving. Imagine a mass of watery sediment actually moving across the shallow sea floor. All storms end, and as this one passed, its currents slowed down. Coarse sediments and large shells dropped out of the flow first. They formed the bottom of our stratum. The storm continued to slow down and finer grained sediments with smaller shells settled out of the flow. When the storm was finally gone, it left behind the stratum that we found, coarse grained at the bottom, fine grained above. With time it hardened into what might be fairly called a petrified storm deposit. Geologists sometimes call them tempestites.

This was a truly devastating event, and many shellfish and seaweeds died because of it. But there were no creatures who understood what happened on that day and certainly none who would go on to even remember it. There never was any record or memory of this storm until hundreds of millions of years passed, when unusually bright primates came along and took a good look at these rocks.

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

“Twenty-one trees”

The Catskill Geologists

Robert and Johanna Titus

We belong to and are active with a large number of local civic groups. Such memberships are rewarding things to do, and they involve us directly with our community in very special ways. We work actively with the Mountaintop Historical Society, the Green County Historical Society, Cedar Grove — the Thomas Cole National Historical Site, Olana, the Woodstock Land Conservancy, WIOX FM and numerous others. Each serves the needs of the broader community (mostly) on a volunteer basis, that’s something that makes the Catskills and the Hudson Valley great places to live. As active scientists, we bring something special to each of these groups; we plug them into their natural histories. It’s a privilege and even an honor to do so. These are interesting and fun endeavors. We urge you to join some of these groups yourself.

Let’s talk about one of the projects that we have been working on recently. That involves the Mountain Top Arboretum, the only public garden/arboretum in all of the Catskills Park. It’s been around since 1977 and has been dedicated to displaying and managing a forest ecology native to our portion of the Northeast. During this time the Arboretum grounds have grown from 7 to 178 acres of forest and meadow. As any arboretum does, it maintains a host of tree species, most of them are native but some are special exotics. We will describe some of these special ones in future columns.

Recently the Arboretum has built and opened a new Education Center. In association with that event, they have sponsored a general survey of the natural history of the Arboretum grounds. They enlisted a number of specialists to study the Arboretum landscapes’ forest history, animals, birds, insects, geology and much more. They approached us to do the geological part and we gladly agreed. It involved a fair amount of work and attendance at a number of planning sessions, but it was all for a good cause. One of the results was a voluminous natural resource inventory which came out last April. Currently, that isn’t for sale to the general public.

But, more recently, a second volume was issued and that is the one we would like to highlight today. It’s entitled “TWENTY-ONE TREES” and it is available for you, the general reader. It’s beautiful book with many fine photographs by Rob Cardillo. The book title refers to the 21 species of native trees that provided the lumber for the Education Center. We wrote an early chapter where we introduce our readers to the geological history of the Arboretum as it can be seen when walking around the grounds, we take people to some of the best bedrock exposures and from there we journey into the Devonian past. We visit the Catskill Delta and some of the streams that flowed by way back then. Then we skip through about 375 million years and visit the Arboretum during the Ice Age. Again, we walk the grounds again and point out the landscape features produced by the ice.

Forest historian Dr, Michel Kudish then takes over and leads readers through the area’s forest history. Mike describes a forest that is gradually recovering from a history of 19^th Century damage done by the tanning industry and farming. Then he describes some of the Catskills oldest peat bogs, dating all the way back to the very end of the Ice Age.

The bulk of the book is devoted to well-illustrated descriptions of the mostly native species of trees found at the Arboretum. Ron Cardillo’s unforgettable year-round photography is the highlight of the book. We recommend it strongly for all of you fascinated by the natural history of our Catskills. Don’t forget, Christmas is coming up and you can only get the book at the Arboretum. It’s a good excuse for a visit. Bring the kids.

Contact the authors at randjtitus@prodigy.net. Join their facebook page “The Catskill Geologist.” Learn more about the Mountain Top arboretum at mtarboretum.org.

An outcrop near Prattsville

The Catskill Geologists; The Mountain Eagle; Nov. 8, 2019

Robert and Johanna Titus

We are guessing that, almost every day, you drive past roadside outcroppings on your routine travels. And we are guessing that you rarely take much notice of them. They are, after all, just rocks. Well, we are in the business of noticing outcrops and sometimes they are quite interesting. We saw one recently on our way home from an event in Prattsville and it was very stimulating. You take Rte. 23 east from Prattsville and turn left where the highway heads toward Windham. Go north about ¾’s of a mile and there it is.

The upper reaches of the strata are fairly run of the mill Catskill sandstones. We didn’t find them all that interesting; it was what we saw below that caught our attention. There, we found about ten feet of poorly stratified, shaley rocks. We are just a little bit uncomfortable in using the word “shaley.” Proper shales are horizontal strata which are also thinly laminated. These were horizontal enough but gently crinkled. Most shales are also usually black or dark gray; these strata were brick red. One of us tugged on his beard; the other furrowed her brow. Both of us were puzzled.

Then it all got worse; at the very bottom of the outcrop the strata were green, not a bright green but a strong enough hue. We could not help but to take special notice of this seemingly out of place color. Green is a rare tint in Catskills strata. But, no matter, red and green it was; there had to be an explanation for these perplexing colors. There was.

Geologists, all around the world look at red strata and reflexively react by uttering the word “terrestrial.” Brick red is the typical color of terrestrial sediments, especially in tropical landscapes. We knew that all these deposits had formed on something called the Catskill Delta. And we also knew that way back then, during the Devonian time period, that delta had lain about 20 degrees south of the Equator in a definitely tropical setting. This outcrop was a partial cross section of that delta, but could we be a little more specific?

We at first wanted to call these red strata paleosols – that word means fossil soils. But we were uncomfortable with that term, fossil soils are usually a good bit more structured than these were. They often display the kinds of A, B and C horizons of typical soils. Ours didn’t, so what was it? Once again beards were tugged, and brows were furrowed. Our final answer involved just the least bit of waffling; we called all this an overbank deposit, not a soil. These fine-grained strata had been deposited as some sort of floodplain sediments and then only just a few soil forming processes began.

All this led to our final story which took us back to a time of drought on the Devonian Catskill Delta. Those floodplain deposits had dried out, exposing them to a lot of oxygen. That oxygen combined with iron to form an iron oxide mineral called hematite which is brick red. That colored the future rocks. But, even during a bad drought, there would still be some water deep in these soils. The water table had been about eight feet deep and down there, without much oxygen, the soils turned green.

So, we have what scientists call a hypothesis to explain what we see along the road. A hypothesis makes sense and is consistent with the evidence. But we are not absolutely sure that we are right and that is why we can’t yet call it a scientific theory. Hypothesis or theory: there is a difference. We don’t know which but still, it is a nice story.

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

A glacier at Pratt Rock

The Catskill Geologists

Robert and Johanna Titus

We were happy to read in the Mountain Eagle of plans for the upcoming restoration of Pratt’s Rock. It’s quite an unusual location; it’s been there a long time and does need an upgrade. We look forward to seeing what will happen, and we hope, when things are done, there will be some appreciation for the geological heritage of this fascinating rock.

Had all gone to plan then Zadock Pratt would have had quite the Mausoleum up there, but that did not happen. Nevertheless, Pratt does have an impressive monument. Probably most all of you have visited it. Many of you have climbed up and seen closeup the carvings that are there. There is still a chamber where Pratt planned to be buried. Then there is the poignant image of Pratt’s son George who died at the Civil War’s Second Battle of Bull Run.

None of this would have or could have been if there had not been such a steep slope there to begin within. Take a look at our first illustration; it shows a topographic map of Pratt’s Rock. Can you “read” contour lines? Then you will recognize the steep Pratt Rock slope from the closely spaced contours. It’s nearly a cliff and it faces the valley of Schoharie Creek which flows through Prattsville. Ledges of Catskill sandstone tower above the valley. A ledge is just a ledge, isn’t it? Well, not where we come from; we are geologists, and we know there is a deeper story here

We hike up to the carvings and then continue onwards to a ledge that offers a fine view of the valley. See our second illustration, a photo of that ledge. Notice the smooth surface and the sharp drop-off of the ledge; there is a cliff there. Less obvious, but quite important, are the scratches on that surface. There is a lot of ice age history here. We look and we see what is called the Schoharie Creek glacier passing by. It has flowed south, swelled up to fill the valley and passed across this sandstone. The ice carried a lot of sand with it, mostly concentrated at its dirty bottom. That sand acted as sandpaper and produced the flat surface. There was more, the glacier carried cobbles and boulders along with the sand. They were dragged across this surface and that produced those scratches which geologists call striations. Knowing this, now you can see that they parallel the glacier’s movement down the valley.

What about that cliff? That’s all part of the same story. Glaciers can be sticky. A glacier, when it passes across a mass of rock such as this, forms a tight bond with it. The glacier continues its journey south, it exerts a tug upon that rock. It is quite possible that the tug will break loose a mass of rock and yank it loose. That’s what happened here. There is nothing unusual about this; we geologists see such things frequently. It has a name; we call it glacial plucking. We stand at the top of this cliff, look down the valley and know that somewhere down there is all that missing rock, buried in the floodplain.

Well, the story we have just related, goes a long way to explain how it was that Pratt’s Rock came to be. It started out as an ice age feature. But there is a lot more to this story. Let’s continue next week.

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