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Title: Variations in sulfur mineralization in the Parachute Creek member of Green River Formation, Colorado and Utah

Conference · · Oil Shale Symp. Proc.; (United States)
OSTI ID:5167130

Sulfur in the Parachute Creek Member of the Green River Formation occurs primarily as pyrite, with lesser amounts of marcasite and pyrrhotite. In this study 222 samples were collected from the openlacustrine facies at Rio Blanco, the marginallacustrine facies at Douglas Pass, and a WOSCO oil shale core drilled in the Eastern Uinta Basin. One portion of each sample was crushed and analyzed for total-weight-percent sulfur (TWPS). Polished blocks were prepared from the remaining slabs. Iron-sulfide morphotypes in these blocks were characterized with a reflected light microscope. Total sulfur contents ranged from 0.0 to 4.6 wt %. Open-lacustrine oil shales in the Parachute Creek Member have much higher relative TWPS values than marginal-lacustrine rocks from the same member. In oil shale, increases in kerogen content are mirrored by increases in total-sulfur content. This correlation is most significant for moderate- to rich-grade oil shales which average between 0.42 and 0.98 TWPS. In oil shale with high relative total sulfur contents, megascopic pods and stringers and microscopic blades, compound-blade clusters and bands, and irregular massive blebs of iron sulfide are the most abundant morphotypes. Stratigraphic variations in sulfur mineralization are present at Rio Blanco. High TWPS values (more than 0.5) are found in the Mahogany ledge and R-8 zone. Rocks above and below this interval have TWPS values less than 0.5. Cyclical stratigraphic variations in TWPS values occur in the Mahogany and R-8 zones.

Research Organization:
ARCO Exploration Co., Denver, CO
OSTI ID:
5167130
Report Number(s):
CONF-830434-
Journal Information:
Oil Shale Symp. Proc.; (United States), Conference: 16. oil shale symposium, Golden, CO, USA, 13 Apr 1983
Country of Publication:
United States
Language:
English