Donald Kenney (donaldkenney@gmail.com)
Last Update: Sat Jul 7 11:16:05 2018


An exposure of Lower Devonian sandstones near Highland Mills, NY

The Site(s)



41.3453N, -74.1200W

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Rules and Access

An active and very busy rail line. The trains are moving fast and are quiet. Not a great place for pets and/or children. There are also exposures on the adjacent thruway, but pedestrians are generally banned from Interstate Highways. There is some poison ivy growing over part of the exposure.

Related Localities

Similar outcrops are found on the adjacent NY State Thruway (Interstate 87). In addition a somewhat similar sequence is found about 8km to the North West of Cornwall New York and around 6km West at Monroe. The sequence at Cornwall-Orrs Mills includes Helderberg Age rocks with reportedly abundant fossils that are part of the unexposed rocks in the Highland Mills exposures.


Molds of brachiopods (39 genera), corals, etc. ichnofossils (16 genera of tracks and burrows)


The beds here are at the North end of the Green Pond outlier -- a 96km long ridge of Lower Paleozoic rocks found East of, and parallel to, the Applachian Mountains in New York and adjacent New Jersey. The outlier is roughly 50km SouthEast of the parallel exposures of similar rocks in the Applachian ("Catskill" in this case) Mountains.

Formations (youngest first)

The specific beds generally collected from at this site in the Highland Mills member of the Esopus formation.

The full sequence exposed in the neighborhood of Highland mills is

Checked 110512 -- The strata here are nearly vertical. Ichnofossils seem to be present in a number of beds, but body fossils seemed to be confined to 10-20 cm of very hard sandstone. You are going to need hardrock mining gear if your interest goes beyond picking over the limited amount of material in the small talus pile.

Other Stuff


Copyright, Licensing, and such

Copyright 2010 Donald Kenney (Donald.Kenney@GMail.com). Unless otherwise stated, permission is hereby granted to use any materials on these pages under the Creative Commons License V2.5 see http://creativecommons.org/licenses/by/2.5/.

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