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Title: Unconformity-bounded Paleocene conglomerate sequence, southeastern Uinta basin

Conference · · Am. Assoc. Pet. Geol., Bull.; (United States)
OSTI ID:7230385

A Paleocene conglomerate and conglomeratic sandstone sequence unconformably overlies locally bleached, nonmarine Campanian rocks and records the first Tertiary depositional event in the southeasternmost part of the Uinta basin, northeastern Utah and northwestern Colorado. This unit is 50 m thick near Sego Canyon. It thins progressively eastward and is only locally preserved over the Douglas Creek arch. The western pinch-out, apparently controlled by the San Rafael uplift, is in the present vicinity of the Green River. Clasts in the conglomerate are mainly rounded to well-rounded pebbles of chert, quartzite, and silicified limestone, ranging in diameter from 4 to 100 mm and averaging 25 to 30 mm. Depositional cycles are common in this sequence. They average 7 m thick and generally fine upward from structureless and crude horizontally stratified conglomerate containing thin sandstone lenses to trough cross-stratified and locally horizontally stratified sandstone and conglomeratic sandstone. These cycles represent multiple episodes of channel cut-and-fill in braided rivers flowing in a medial to distal braid-plain setting. Transport was dominantly from the south, but rivers swung to the northwest along the northeastern edge of the San Rafael uplift and to the northeast along the northwestern edge of the Uncompahgre uplift.

Research Organization:
Geological Survey, Denver, CO
OSTI ID:
7230385
Report Number(s):
CONF-8609129-
Journal Information:
Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 70:8; Conference: AAPG Rocky Mountain Section meeting, Casper, WY, USA, 7 Sep 1986
Country of Publication:
United States
Language:
English