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. [1]

Glens Falls

Stratigraphic range: Late Ordovician
TypeFormation
Unit ofTrenton Group
Sub-units
  • Shoreham Member
  • Larrabee Member
OverliesAmsterdam Limestone
Lithology
PrimaryLimestone
OtherShale
Location
Region New York
 Ontario
CountryUnited States
Canada
Type section
Named forGlens Falls, NY
Named by(RUEDEMANN, 1912)

Stratigraphy edit

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.[2]

Fossils edit

Trilobite Cryptolithus[3]

Economic Uses edit

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

References edit

  1. ^ "Geolex — GlensFalls publications". ngmdb.usgs.gov. Retrieved 2023-09-15.
  2. ^ David A. MacLean FACIES RELATIONSHIPS WITHIN THE GLENS FALLS LIMESTONE OF VERMONT AND NEW YORK
  3. ^ Fisher, D.W., 1965a, Mohawk Valley Strata and structure; New York State Geological Association field guide, 37th Annual meeting, Union College