Intertongued Dakota Sandstone-Mancos Shale members of surface and subsurface in San Juan basin, New Mexico and Colorado

Conference · Fri Jan 01 00:00:00 EST 1988

OSTI ID:5923696

Owen, D E; Walters, Jr, L J; Sparks, D K

Three wedges of transgressive marine Mancos Shale, deposited offshore, intertongue with four Dakota Sandstone units, largely shoreface deposits. Contacts between shoreface and offshore lithologies trend approximately north-south, with nonmarine Dakota main body sandstones to the west. Submarine bar sandstones trending northwest-southeast are locally developed near the shoreface-offshore transition. This succession was deposited during approximately 4 m.y. of the transgressive phase of the Greenhorn cyclothem. Each Dakota-Mancos sandstone-shale pair may represent (1) a fourth-order eustatic cycle or (2) regional tectonic and local sedimentologic overprints of two third-order Vail cycles. Detailed analyses of trace elements within shales and primary sedimentary structures and trace fossils of sandstones, combined with geophysical logs and regional paleontologic control, were invaluable in this first, basin-wide, surface and subsurface paleoenvironmental study of these complex strata.

• OSTI ID: 5923696
• Report Number(s): CONF-880301-
• Resource Relation: Conference: Annual meeting of the American Association of Petroleum Geologists, Houston, TX, USA, 20-23 Mar 1988
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
04 OIL SHALES AND TAR SANDS
COLORADO
PETROLEUM DEPOSITS
NEW MEXICO
SEDIMENTARY BASINS
GEOPHYSICAL SURVEYS
GEOCHEMISTRY
ONSHORE SITES
PALEONTOLOGY
CHEMISTRY
FEDERAL REGION VI
FEDERAL REGION VIII
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
SURVEYS
USA
020200* - Petroleum- Reserves
Geology
& Exploration
040201 - Oil Shales & Tar Sands- Site Geology- (-1989)
040500 - Oil Shales & Tar Sands- Properties & Composition