Source area and depositional controls on diagenesis in the deep lower Tuscaloosa Formation (Upper Cretaceous), Gulf Coast

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6060765

Weedman, S D; Brantley, S L ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States). Geosciences Dept.

Sandstone cores from two widely separated gas fields within the deep lower Tuscaloosa Formation were sampled and examined with optical, cathodoluminescent, and scanning electron microscopy. Diagenetic differences between the two areas (the Moore-Sams/Morganza (MS/M) and Rigolets (R) fields) can be explained by different source areas and depositional environments. The coarsening-upward reservoir sandstones of the MS/M fields were deposited along a prograding delta front, where sand/shale ratios of at least 4:1 indicate extensive sandstone connectivity. Sandstone isolith maps suggest a source area to the north including areas of contemporaneous (Cenomanian) alkaline volcanic activity in Louisiana, Mississippi, and Arkansas. The sandstones have extremely high porosity, interpreted as secondary, despite burial depths. Porosity is preserved where compaction is inhibited by relict cements and overpressures. Additionally, pores are lined with an iron-rich chlorite, which inhibits late quartz cement. Sedimentary structures and sand/shale ratios in lower Tuscaloosa sandstones of the R field suggest more distal, shale-dominated depositional environments. Sandstone isolith maps indicate a source area to the northeast, to sandstones of the MS/M fields, R field sandstones are richer in feldspar, pore-filling kaolinite and calcite, and lack recognizable volcanic rock fragments. Secondary porosity and chlorite in these sandstones are rare.

• OSTI ID: 6060765
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ALABAMA
NATURAL GAS DEPOSITS
DIAGENESIS
CRETACEOUS PERIOD
DEPOSITION
NATURAL GAS FIELDS
POROSITY
SANDSTONES
SOURCE ROCKS
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
030200* - Natural Gas- Reserves
Geology
& Exploration