Earth:Indian Point Formation

Indian Point Formation Stratigraphic range: Ludlow epoch ~423–419 Ma PreЄ Є 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
Paleocoordinates	[ ⚑ ] 26.6°S 29.7°W / -26.6; -29.7
Region	Quebec
Country	Canada
Extent	Gaspe National Park
Indian Point Formation (Canada) Indian Point Formation (Quebec)

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

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.

Fossil content

The following fossils were reported from the formation:

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

References

Bibliography

• Plotnick, R. E. 1999. Habitat of Llandoverian-Lochkovian eurypterids, 106–136. in A. J. Boucot, J. D. Lawson (eds.), Paleocommunities - a case study from the Silurian and Lower Devonian.