Seismic-scale outcrops of oblique clinoforms, Topatopa Mountains, southern California

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:7033367

Clark, M S ^[1]; Abbott, W ^[2]

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1. Colorado School of Mines, Golden (USA)
2. Occidental International Exploration and Production Co., Bakersfield, CA (USA)

The Devil's Heart region of the Topatopa Mountains offers an unusual opportunity to describe, measure, and interpret reservoir-scale facies distributions with respect to seismic-scale stratal geometries. Seismic-scale outcrops of middle Eocene siliciclastic, progradational deltas show stratal geometries and facies distributions parallel and perpendicular to paleoshoreline. Landward-stepping, shoaling-upward cycles with parallel-concordant geometries are overlain by oblique clinoforms. The clinoforms are truncated by toplap against a sequence-bounding disconformity that represents a surface of sediment bypass and erosion. The sequence boundary, in turn is overlain by a second set of landward stepping, shoaling-upward cycles with parallel-concordant geometries. Thus, the deltas prograded episodically across a marine basin and filled the basin nearly to sea level. A deepening event ended progradation and marked a return to aggradational processes. Stratal geometries, facies distributions, and petrophysical properties were used to generate a synthetic seismic profile on which sedimentary facies and depositional environments were superimposed. This synthetic profile was then restored to a depth of 13,000 ft (2.0-2.1 sec) and used as a model to interpret the distributions of facies and depositional environments for actual seismic data from other areas. The model shows continuous reflections from basin facies to the delta top. This contrast with observations of the outcrop that show discontinuity of strata at the upper sequence boundary. By superimposing the facies on the synthetic seismic line, it is possible to show that delta-front turbidites and slumped strata comprising the clinoform bottomsets and foresee are not connected to wave-dominated river and/or delta mouth bars comprising the topset strata. This underscores the importance of having the outcrop model to correctly interpret the seismic.

• OSTI ID: 7033367
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
CALIFORNIA
EXPLORATION
FEDERAL REGION IX
GEOLOGIC DEPOSITS
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
MINERAL RESOURCES
NORTH AMERICA
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
SEISMIC SURVEYS
STRATIGRAPHY
SURVEYS
USA