USGS Mesozoic loc. 20008 (Jurassic of the United States)

Where: Alaska (59.8° N, 153.2° W: paleocoordinates 28.8° N, 84.9° W)

• coordinate estimated from map

When: Gaikema Formation (Tuxedni Group), Bajocian (170.3 - 168.3 Ma)

• Bajocian, base of Gaiema Sandstone (Detterman and Hartsock, 1966)

Environment/lithology: marine; massive, coarse-grained, gray, yellow, conglomeratic sandstone and siltstone

• Sandstone, massive, locally conglomeratic; minor siltstone

•"Sandstone medium bedded to massive medium to coarse grained olive gray to dusky yellow green weathers dark brown lenticular beds of pebble cobble conglomerate silty shale and siltstone in lower part of unit one thin bed of chocolate brown friable sandstone near base of unit many coquina beds Witchellia Trigonia and Inoceramus." (Detterman and Hartsock, 1966)

•"The Gaikema Sandstone Member, named by Kirschner and Minard (1948) after Gaikema Creek on Iniskin Peninsula, is herein designated the Gaikema Sandstone.

•The type locality is designated as the left bank of the creek, starting 5,000 feet frO'm the mouth and continuing for 1,800 feet upstream. The section at the type locality is 850 feet thick and consists of resistant cliff forming sandstone, in part conglomeratic. Siltstone, shale, and cobble-boulder conglomerate are subordinate constituents." (Detterman, 1963)

Size classes: macrofossils, mesofossils

Collected by H. Wedow and L.B. Kellum in 1944; reposited in the USNM

Primary reference: T. P. Poulton. 1979. Jurassic Trigoniid Bivalves from Canada and Western United States of America. Geological Survey of Canada Bulletin 282 [G. Stanley/H. Shepherd/H. Shepherd]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 139549: authorized by George Stanley, entered by Hannah Shepherd on 13.02.2013

Creative Commons license: CC BY (attribution)

Taxonomic list

 Trigoniida - Myophorelloidae
Myophorella dawsoni Whiteaves 1878 clam