Mineralogy and diagenesis of low-permeability sandstones of late cretaceous age, Piceance Creek Basin, northwestern Colorado

Journal Article · Wed Oct 01 04:00:00 EDT 1980 · Mt. Geol.; (United States)

OSTI ID:7087089

Hansley, P L; Johnson, R C

This report presents preliminary results of a mineralogic and diagenetic study of some low-permeability sandstones from measured surface sections and cores obtained from drill holes in the Piceance Creek Basin of northwestern Colorado. These sandstones are in the nonmarine upper part of the Mesaverde Formation (or group) of Late Cretaceous age and are separated from overlying lower Tertiary rocks by a major regional unconformity. Attention is focused on the sandstone units of the Ohio Creek Member, which directly underlies the unconformity; however, comparisons between the mineralogy of the Ohio Creek strata and that of the underlying sandstone units are made whenever possible. The Ohio Creek is a member of the Hunter Canyon Formation (Mesaverde Group) in the southwestern part of the basin, and the Mesaverde Formation in the southern and central parts of the basin. The detrital mineralogy is fairly constant throughout all of these nonmarine Cretaceous sandstone units; however, in the southeastern part of the basin, there is an increase in percentage of feldspar, quartzite, and igeneous rock fragments in sandstones of the Ohio Creek Member directly underlying the unconformity. In the southwestern part of the basin, sandstones of the Ohio Creek Member are very weathered and are almost entirely comprised of quartz, chert, and kaolinite. A complex diagenetic history, partly related to the overlying unconformity, appears to be responsible for transforming these sandstones into potential gas reservoirs. The general diagenetic sequence for the entire Upper Cretaceous interval studied is interpreted to be (early to late): early, calcite cement, chlorite, quartz overgrowths, calcite cement, secondary porosity, analcime (surface only), kaolinite and illite, and late carbonate cements.

• Research Organization: Geological Survey, Denver, CO
• OSTI ID: 7087089
• Journal Information: Mt. Geol.; (United States), Journal Name: Mt. Geol.; (United States) Vol. 17:4; ISSN MOGEA
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030200* -- Natural Gas-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580300 -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
COLORADO
DATA
DIAGENESIS
EXPERIMENTAL DATA
GEOLOGIC DEPOSITS
INFORMATION
MINERAL RESOURCES
MINERALOGY
NATURAL GAS DEPOSITS
NORTH AMERICA
NUMERICAL DATA
PERMEABILITY
PICEANCE CREEK BASIN
RESERVOIR ROCK
RESOURCES
ROCKS
ROCKY MOUNTAIN REGION
SANDSTONES
SEDIMENTARY ROCKS
STRATIFICATION
USA