Lewis shale reservoirs, southern Wyoming: turbidite sandstones deposited in delta-toe settings
Conference
·
· Am. Assoc. Pet. Geol., Bull.; (United States)
OSTI ID:5848701
Depositional history of the Lewis Shale, Maestrichtian, south-central Wyoming, consists of a transgressive period followed by an interval of delta infill. Clastics are up to 760 m thick. The Lewis sea transgressed westward to areas of the Rock Springs and Wind River uplifts and opened eastward into the main part of the Interior Seaway. Transgressive shales are black, high in organic material, relatively silt-poor, and totally bioturbated. Depositional setting was a shallow, well-oxygenated shelf. Lewis clastics above the transgressive shale are coarser and are related mostly to deltas that entered the basin first from the northeast and later from the south. Sediments were deposited in delta-front, prodelta, deep-basin, and interdistributary areas. Lewis sandstones produce at Wamsutter and Hay Reservoir fields in addition to other areas. Wamsutter and Hay Reservoir sandstones were deposited beneath storm wave base by sediment gravity flows at the toe of the northern delta system. Sandstones may be thickly bedded and are commonly massive. Presence of fluid escape structures indicates that many thick beds underwent liquefaction during the final stages of deposition. Thinner sandstones are graded and many show Bouma sequences. Interbedded shales are unburrowed or are slightly burrowed by restricted faunas, indicating anaerobic to dysaerobic conditions and water depths of 150-200 m or more at times.
- Research Organization:
- Marathon Oil Co., Littleton, CO
- OSTI ID:
- 5848701
- Report Number(s):
- CONF-850322-
- Conference Information:
- Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 69:2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Shallow-water and sub-storm-base deposition of Lewis Shale in Cretaceous Western interior seaway, south-central Wyoming
Variability of deltaic sedimentation during clastic influx into a carbonate-dominated craton
Paleoenvironments of Upper Cretaceous Lewis Shale and Fox Hills Formation, south-central Wyoming
Journal Article
·
Wed Jul 01 00:00:00 EDT 1987
· AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)
·
OSTI ID:5968907
Variability of deltaic sedimentation during clastic influx into a carbonate-dominated craton
Conference
·
Mon Dec 31 23:00:00 EST 1984
· Geol. Soc. Am., Abstr. Programs; (United States)
·
OSTI ID:6458481
Paleoenvironments of Upper Cretaceous Lewis Shale and Fox Hills Formation, south-central Wyoming
Conference
·
Thu Dec 31 23:00:00 EST 1987
·
OSTI ID:6127732