Indian Point Formation

Stratigraphic range: Ludlow epoch
~423–419 Ma

PreꞒ

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 / 48.8; -64.5
Approximate paleocoordinates| 26°36′S 29°42′W﻿ / ﻿26.6°S 29.7°W﻿ / -26.6; -29.7
Region| Quebec
Country|  Canada
Extent| Gaspe National Park

Indian Point Formation (Canada)

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Indian Point Formation (Quebec)

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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]

* Waeringopterus sp.

### Pterobranchia[edit]

* Monograptus nilssoni

## 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]

1. ^ a b Indian Point Formation at Fossilworks.org
2. ^ Eurypterid-associated biota of Indian Point Fmn. in Gaspe National Park at Fossilworks.org
3. ^ Plotnick, 1999

### Bibliography[edit]

* 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.