Influence of depositional environments on origin of secondary carbonates and diagenesis of organic matter, Tertiary basinal units, La Honda basin, Santa Cruz Mountains, California

Conference · Wed Mar 01 04:00:00 EST 1989 · AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States)

OSTI ID:6085553

Hollander, D J; Garrison, R E

A comparative study of authigenic carbonates formed in five organic-rich, deep-water units of the La Honda basin indicates that sedimentation rate and degree of bottom-water oxygenation ultimately controlled the timing, chemical environment, mineralogy, and rate of authigenic carbonate formation. Additionally, sedimentation rate and oxygenation of bottom water governed the sequence of diagenetic chemical environments, the degree of preservation of organic matter, and the source bed potential of the basinal units. The conditions necessary for the preservation of organic matter and the development of potentially good source rocks were variable. However, the occurrence of anaerobic bottom waters was the critical element in the development of excellent source rocks (i.e., Twobar Shale Member, Lambert Shale) regardless of the rate of sedimentation or the rate of primary productivity. In contrast, in basinal units characterized by oxygenated bottom waters, high rates of sedimentation, and high rates of primary productivity (Monterey Formation and Santa Cruz Mudstone Member), rapid burial of organic matter promoted highly anaerobic diagenetic environments which decreased the rate of organic matter decomposition, thereby producing units with good potential source rocks.

• Research Organization: Swiss Federal Institute of Technology, Zurich
• OSTI ID: 6085553
• Report Number(s): CONF-890404-
• Conference Information: Journal Name: AAPG (Am. Assoc. Pet. Geol.) Bull.; (United States) Journal Volume: 73:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
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CALIFORNIA
CARBONACEOUS MATERIALS
CARBONATE ROCKS
DEPOSITION
DIAGENESIS
FEDERAL REGION IX
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
MATERIALS
MINERAL RESOURCES
NORTH AMERICA
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ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SHALES
SOURCE ROCKS
USA