Sunday, April 10, 2011

Fossil collecting fieldtrip

Saturday (April 9), I took a small group of students from my Earth History class on an all-day fieldtrip to collect some fossils (Earth History is our 4 credit historical geology course).  While we have looked at sedimentary rocks and Paleozoic marine invertebrate fossils in lab, it's always valuable to see them out in the field as well.

The day started chilly (I scraped frost off my car at 7:30 am) but soon warmed to above 60 F.  A 90 minute scenic drive up through the heart of the Catskills brought us to Gilboa - a locality famous to geologists around the world since it's the site of the first forest we have abundant fossils from in the Middle Devonian Period (~380 million years ago).  There is an informative outdoor kiosk off County Route 990V next to the Gilboa Post Office which has some large fossils on display.

Here's a close-up of the Devonian forest reconstruction on the kiosk.

Yes, New York really once looked like that.  A lowland swamp south of the equator in a subtropical climate zone.  Notice the bulbous bases of the Eospermatopteris trees?  Here's the fossil:

There were some neat fossils discovered in Gilboa, including insects, and it's an interesting story but I'll save it for another post.  We also took a walk and poked around a bit down by the Scoharie Creek where we were able to find some plant fossils in weathered red (terrestrial) sandstones (I'm not a fossil plant expert but the first one is a piece of branch or large root and the other is a bit difficult to see in the photo but is clearly root material).

I also saw a nice slab of sandstone with asymmetrical ripple marks (river bed environment?). I would have loved to bring back to the lab as a teaching specimen except for the fact that I would have had to carry it up a steep hill!

There were also some out-of-place early Devonian carbonate rocks (Manlius, Coeymans, and Kalkberg Formations of the Helderberg Group) dumped there for flood control which also contained some neat fossils.  See the trilobite fragment next to the brachiopod shell?  The one below looks like a cephalopod (squid-like animal) - it's definitely not a crinoid stem (we found others as well).

For lunch, we drove north to Middleburg and hiked up to Vroman's Nose.  It's a short, steep hike but well worth it when you get to the top - highly recommended.  Here's the view looking south of the beautiful Schoharie Valley.

At the top is a large flat rock (Hamilton Group sandstone) called the Dance Floor.  It's loaded with glacial striations.  After chilling (catching our breath from the climb up) and eating lunch, I discussed the glacial features visible here and talked about post-glacial Lake Schoharie which once filled the valley below.   I also said a few things about meandering rivers and floodplains.

From Middleburg, we drove up to Schoharie where I had read about a good fossil collecting outcrop just outside of town on Rickard Hill Road.  It's a nice roadside outcrop of Coeymans and Kalkberg Formation (lower Helderberg Group) with a large area to collect well off the road (the cliffs were unstable but there was plenty of stuff on the ground).  The rocks were extremely fossiliferous with numerous brachipods, lots of bryozoa fragments, a few pieces of trilobites (most students were unsuccessfully looking for good trilobite specimens), and some Favosites corals.

Here are some students looking for fossils...

Here's a Favosites (honeycomb) coral I picked up in the Kalkberg Formation and below that, some Gypidula brachipods from the Coeymans Formation.

Not a bad way to spend a Saturday.

By the way, for all those who think professors have easy jobs, are lazy, whatever (which many people evidently do given the recent union-busting events in Wisconsin and the fact that State legislators in a number of places are out to get higher education faculty), I will add that I do this for free.  I don't get paid extra for taking students out on field trips on Saturdays.  I work Saturdays like this several times a year.  It takes time to plan, I have the responsibility of keeping students safe, I have to drive hundreds of miles (200 miles on the college van odometer Saturday), and it even costs me some money (it's such a hassle to submit the couple of dollars in Thruway tolls I don't even bother).  Why do I do it?  I CARE ABOUT THE STUDENTS!  You can't learn geology well only in a classroom - you have to get outside, get dirty, hot, and tired, and look at the damn rocks (and fossils).  How many of you would volunteer to work at your job on a Saturday when you didn't have to for no extra money?  If so, count your blessings because it means you love your job!


  1. Great post! I did some work on the Coeymans while at Oneonta, and I'm pretty sure the one fossil that looks like a cephalopod is the holdfast of Lepocrinites gebhardi which is a cystoid.

  2. Thanks very much for the informative post. I found this by googling Hudson Valley Fossil, my seven year old son having discovered, on his own, what he claimed to be a fossil on the Bard campus. It did look like a fossil, but being entirely ignorant on the subject, I was skeptical. Darned if he was right. He was very excited when told him we will make a day trip to some of the sites you mention. Perhaps I have a budding geologist/archeologist on my hands.

  3. Thanks for the post. We wnt to the Rickard Hill site and found lots of good specimens,