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

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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

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Trilobite Cryptolithus[3]

Economic Uses

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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

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  1. ^ "Geolex — GlensFalls publications". ngmdb.usgs.gov. Archived from the original on 2023-09-22. 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