Glens Falls Formation

The Glens Falls formation is the lowest (oldest) unit of the Trenton Group. The Glens Falls is a made up of limestone and contains thin fossiliferous beds. It was most likely deposited in shallow water due to the presence of ripple marks.

Stratigraphy
The Shoreham member is the upper member of the formation. It contains much more clay and silica, resulting in beds of shale. Name after a quarry in Vermont.

The Larrabee Member is the lower member. It contains some clay in silica but has more carbonate material than the Shoreham. Name after a quarry in Vermont.

Fossils
Trilobite Cryptolithus

Economic Uses
The limestone in the Glens Falls has been used for agricultural lime, used as lime for cement manufacturing, and crushed aggregate for road beds.