Also known as M1168
Where: Aleutians East County, Alaska (55.4° N, 161.5° W)
• Paleocoordinates: 66.3° N, 151.4° W (Wright 2013)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Tolstoi Formation, Middle Eocene (47.8 - 37.7 Ma)
• The formation contains the oldest Tertiary rocks on the Alaska Peninsula; marine mollusks were determined as middle Eocene; and plants were dated as probably Paleocene. Neither base or top of sequence is represented in the section, but both are apparent locally. The basal contact shows no sharp angular discordance with the Hoodoo Formation, but black shales and siltstones of both are very difficult to distinguish. The top of the Tolstoi Formation appears to be conformable with Oligocene Stepobak Formation, but the contact is complicated by faulting.
• bed-level stratigraphic resolution
Environment/lithology: marine; brown, gray, green, carbonaceous sandstone and volcaniclastic conglomerate
Size class: macrofossils
Collection methods: quarrying,
• Collections examined by F.S. MacNeil and D. Taylor (USGS), 1962. Collections are reposited at USGS Menlo Park, or presumably USNM (not reported)
Primary reference: C.A. Burk. 1965. Geology of the Alaska Peninsula-island arc and continental margin (Part 1). Geological Society of America Memoir 99(1) [A. Miller/A. Hendy/A. Hendy]more details
Purpose of describing collection: biostratigraphic analysis
PaleoDB collection 44070: authorized by Austin Hendy, entered by Austin Hendy on 31.08.2004
Creative Commons license: CC0 (CC0)
Taxonomic list
Gastropoda | |
Cylichna sp. Lovén 1846 snail | |
Natica sp. Scopoli 1777 moon snail | |
Perse sp. Clark 1918 snail | |
Turritella uvasana Conrad 1855 turret shell | |
Bivalvia | |
Costacallista conradiana Gabb 1864 venus clam | |
"Plagiocardium (Schedocardia) breweri" = Schedocardia brewerii
"Plagiocardium (Schedocardia) breweri" = Schedocardia brewerii Gabb 1864 cockle | |
"Venericardia aff. clarki" = Venericardia (Pacificor) clarki
"Venericardia aff. clarki" = Venericardia (Pacificor) clarki Weaver and Van Winkle Palmer 1922 clam | |