USGS DR 2516, De Long Mountains [Otuk Fm] (Triassic of the United States)

Also known as 00AD4E; Loc. 5 KRA

Where: Alaska (68.3° N, 163.4° W: paleocoordinates 47.3° N, 19.8° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Otuk Formation (Etivluk Group), Ladinian (242.0 - 237.0 Ma)

• STRATIGRAPHIC RELATIONS: From the Otuk Formation of the Etivluk Gp. AGE: Middle Triassic (middle to late Ladinian). STRATIGRAPHIC POSITION: Sample from middle subunit of Otuk Formation (Etivluk Group), below recessive marker.

• bed-level stratigraphic resolution

Environment/lithology: marine; lithified, gray chert

• SPECIFIC LITHOLOGY: Gray chert. Thin section shows abundant, locally well-preserved radiolarians in matrix of cryptocrystalline to fine-crystalline chert, with veins of barite, scattered carbonate crystals, and rare phosphatic bioclasts. LITHIFICATION: Lithified, on the basis of facies description and preparation techniques.

Size class: macrofossils

Primary reference: J. A. Dumoulin, A. G. Harris, C. D. Blome and L. E. Young. 2006. Conodont and radiolarian data from the De Long Mountains Quadrangle and adjacent areas, northern Alaska. United States Geological Survey Open-File Report 2006(106):1-174 [A. Hendy/A. Hendy]more details

Purpose of describing collection: biostratigraphic analysis

PaleoDB collection 91025: authorized by Austin Hendy, entered by Austin Hendy on 31.08.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Show authors, comments, and common names
Protozoa
 Nassellaria - Ruesticyrtiidae
Triassocampe sp.
Triassocampe sp. Dumitrica et al. 1980 radiolarian
 Nassellaria - Pseudodictyomitridae
Corum perfectum
Corum perfectum radiolarian
 Entactinaria - Hindeosphaeridae
Pseudostylosphaera coccostyle, Pseudostylosphaera japonica, Pseudostylosphaera nazarovi, Muelleritortis cochleata
Pseudostylosphaera japonica Nakaseko and Nishimura 1979 radiolarian
Pseudostylosphaera nazarovi Kozur and Mostler 1979 radiolarian