Indian Point Formation
Indian Point Formation | |
---|---|
Stratigraphic range: Ludlow epoch ~ | |
Type | Formation |
Underlies | Archibald Settlement Formation |
Lithology | |
Primary | Sandstone, siltstone, calcarenite |
Other | Biostromal limestone, conglomerate, mafic volcanic rock |
Location | |
Coordinates | 48°48′N 64°30′W / 48.8°N 64.5°W |
Approximate paleocoordinates | 26°36′S 29°42′W / 26.6°S 29.7°W |
Region | Quebec |
Country | Canada |
Extent | Gaspe National Park |
The Indian Point Formation is a geologic formation in Quebec. It preserves fossils dating back to the Ludlow epoch of the Silurian period.[1]
Description
[edit]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
[edit]The following fossils were reported from the formation:[1][3]
Eurypterids
[edit]Pterobranchia
[edit]See also
[edit]- List of fossiliferous stratigraphic units in Quebec
- Bertie Formation, Silurian Lagerstätte in Ontario
- Charlevoix impact structure, Silurian impact structure in Quebec
References
[edit]- ^ a b Indian Point Formation at Fossilworks.org
- ^ Eurypterid-associated biota of Indian Point Fmn. in Gaspe National Park at Fossilworks.org
- ^ Plotnick, 1999
Bibliography
[edit]- Plotnick, R. E (1999), Habitat of Llandoverian-Lochkovian eurypterids, in A. J. Boucot, J. D. Lawson (eds.), Paleocommunities - a case study from the Silurian and Lower Devonian, pp. 106–136