The Esopus formation lies between the Glenerie and the Carlisle Center formations.  It was formed during the early Devonian, and its age is Emsian.  The Esopus is part of a larger group the Tristates.  After the Acadian Orogeny, two small basins were formed by deformation.  The Esopus muds were deposited in the more northern of these two unconnected basins.  They represent a dysaerobic environment dominated by low-oxygen-tolerant fauna.  As mentioned, the Esopus grades up into the Carlisle Center, which is a shift to more normal, aerobic conditions.  The Tristates ranged from middle (outershelf) to offshore environments.  The Esopus represents a deep, quiet water basin.   Its thickness ranges from 200 to 275 ft. 

The Esopus appears to be a monotonous dark siltstone; however, varying mineralogy has allowed division into three distinct members: the Lower, Middle, and Upper Esopus.  The Esopus that we saw in the field trip was black to gray argillaceous siltstone (this can been seen in the color photos of the Esopus, for example, the one below).  The grain size of the Esopus varies from clay to silt to fine sands.  Below is a photo of the class sitting on the Esopus!
 

The only fossils that were observed on this trip were trace fossils, however a certain type of brachiopod can be found near Kingston, NY but this is very infrequent and limited. Zoophycos and Chondrites as well as massive horizontal and vertical burrows filled with limonite are prevalent in the Esopus, (see the burrows in the following three photos).
 

There are two areas in which bedding can be seen in the Esopus.  These areas have been undisturbed by burrowing organisms.  During one of the earlier stops on our field trip, near Catskill Creek and Austin Glen, we were able to see the bedding in the Esopus (go to photo below of bedding, may be difficult to see however due to dark color of formation).
 
 

An antiform was also seen within the Glenerie (see photo below).
 
 

Bordeaux, Yvette.  "Field Trip to the Hudson Valley Region, New York State, Fall 2001".

http://everest.hunter.cuny.edu/bight/index.html
This web site is a collection of short reports and image libraries about the natural history of the New York Bight region. The goal of this project is to provide basic information about the beaches scattered throughout the New York Bight, emphasizing those within Gateway National Recreation Area (New York and New Jersey).

http://www.esopus.com/
Not too helpful for this assignment, there is a town called Esopus, and this is its website!

http://www.hartwick.edu/envirsci/Careers/portfolio/fieldst/catskill.html
Introduction and Geologic Setting of the Hudson Valley Fold-Thrust Belt, route 23, near Catskill, NY (includes lithology, structures, and interpretations).

http://www.dec.state.ny.us/website/dmn/southstrat.htm
The New York State Dept. of Env. Conservation’s Stratigraphic Section for Southwestern New York State.

Dora is in her junior year at UPenn and is a Geology and Environmental Studies double major.  Her main areas of interest are hydrogeology and geophysics.  She is currently planning her senior thesis which will most likely be about the electro-magnetic properties of buried steel drums.