Indian Point Formation

The Indian Point Formation is a geologic formation in Quebec. It preserves fossils dating back to the Ludlow epoch of the Silurian period.^[1]

Indian Point Formation
Stratigraphic range: Ludlow epoch ~423–419 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Formation
Underlies	Archibald Settlement Formation
Lithology
Primary	Sandstone, siltstone, calcarenite
Other	Biostromal limestone, conglomerate, mafic volcanic rock
Location
Coordinates	48.8°N 64.5°W / 48.8; -64.5
Approximate paleocoordinates	26.6°S 29.7°W / -26.6; -29.7
Region	Quebec
Country	Canada
Extent	Gaspe National Park
Indian Point Formation (Canada) Show map of Canada Indian Point Formation (Quebec) Show map of Quebec

Description

The Indian Point Formation comprises thin- to thick-bedded, locally fossiliferous, calcareous siltstones, fine-grained sandstones, calcarenites, and minor biostromal limestones, conglomerates, red siltstones, and mafic volcanic rocks. The Indian Point Formation is conformably overlain by within-plate tholeiitic mafic to intermediate flows and flow breccias of the Archibald Settlement Formation, developed as a synsedimentary normal fault in the Late Silurian, based on the presence of polymictic conglomerate beds in a thickened Indian Point section east of the fault. Post-Early Devonian (Acadian) orogenic events have produced open to close folds with northeast-trending axes.^[2]

Fossil content

The following fossils were reported from the formation:^[1][3]

Eurypterids

• Waeringopterus sp.

Pterobranchia

• Monograptus nilssoni

See also

• List of fossiliferous stratigraphic units in Quebec
• Bertie Formation, Silurian Lagerstätte in Ontario
• Charlevoix impact structure, Silurian impact structure in Quebec