Also known as M1170, UCMP IP21018

Where: Aleutians East County, Alaska (55.4° N, 161.5° W: paleocoordinates 62.4° N, 151.6° W)

• 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); collections transferred to UCMP

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 44069: authorized by Austin Hendy, entered by Austin Hendy on 31.08.2004, edited by Patricia Holroyd

Creative Commons license: CC BY (attribution)