The Catskill Geologists with Robert and Johanna Titus - Grand Gorge Stopping Along the Road

CATSKILL - Last time, we visited Grand Gorge and learned about its ice age origins. We watched as enormous volumes of glacial meltwater rushed by. That took us about 15,000 years into the past to a moment late in the Ice Age. Does that seem a long time ago? Well, it probably does to an average human being. We are, after all, only given “three score and ten” years on this planet.

The space occupied by Grand Gorge has been where it is today for a very long time. It’s a spot; it has a longitude and latitude that has been there for four and a half billion years. This spot has been here all of that time and it has, of course, changed a lot. What was it like here a million years ago? How about a hundred million? Well, it is up to geologists to figure out what happened during all of that time.

Let’s see what we can learn about Grand Gorge. If you drive in from the north you will pass a Firestone agency. Go another half mile and you see an outcropping of stratified rock on the right (west) side of the highway. That begins our journey into the past. Take a good look at our photo; the strata of the upper half of the outcrop are all inclined to the left. We believe we are looking at the sediments of an ancient stream channel. The bedding dips leftward, towards the deepest part of the stream.

   If you park and get out. You can walk up to those strata and touch them. You are literally standing in the flow of that river. Perhaps you can even feel the river currents coming from behind you! River channel deposits are common throughout the Catskills. But, what an experience it is to recognize one. This is a petrified river!

   If you scan downwards you will discover a few feet of poorly stratified, brick red rock at the bottom of the outcrop. The color is a giveaway; it is the color of many modern tropical soils. We are looking at petrified soils that once lay along the banks of our petrified river. If you visit the modern lands of the Amazon or Congo basins, you will see similar soils.

   What about the strata in the middle? They are flat lying strata, lying above the soils and below the river channel. We really are not sure how they formed. Sometimes a scientist just has to guess, and we are guessing that these strata formed as the deposits of a river levee, sediments on the bank of the old river.

   So, we stopped along the side of the road and looked at some ancient rocks. We found a mix of river and floodplain deposits; we think we are looking at an ancient delta – it’s called Catskill Delta, and we talked of it recently in our column.

   But how old is all this?   We did not find any fossils but others have. They all belong to a time called the Devonian time period. The makes these strata approximately 350 to 375 million years old.

   We have traveled to Grand Gorge as it was during the Devonian, We traveled to an ancient tropical delta. We traveled through time.

     Contact the authors at randjtitus@prodigy.net. Join their facebook page The Catskill Geologist or visit their blog thecatskillgeologist.com