Transpressional piggyback basin in southern Diablo Range, California

Conference · Tue Apr 01 04:00:00 EST 1986 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6886515

Rentschler, M S

Piggyback basins, as defined by G.G. Ori and P.F. Friend, are basins that are trapped when a thrust system propagates into its foredeep. Strata of the newly formed piggyback basin lap onto the growing outer thrust ridge that separates it from the foredeep. As thrust movement continues, piggyback basin fill passes from deep-water to shallow-water facies, and depositional sequences become progressively decoupled from those in the foredeep. Neogene structural evolution and depositional sequences in the southern Diablo Range between Panoche and Coalinga show a similar history. The southern Diablo Range consists of three structural domains: (1) a band along the San Andreas fault where the major structures are subparallel to the fault, (2) an intermediate zone where major fold axes are arranged en echelon, and (3) the eastern front of the range, which trends subparallel to the San Andreas fault. The en echelon folds of domain 2 suggest that it is a zone of dextral transpression. Northeast-directed thrust faults probably underlie domain 3, suggesting that the southern Diablo Range as a whole is a northeast-verging transpressional fold and thrust belt. Deposition occurred synchronously with transpression in the Vallecitos syncline of the southern Diablo Range. The Saucesian and Relizian Temblor Formation of the eastern syncline, as deep as upper bathyal, thins and laps onto flanking en echelon folds and onto the growing, intermittently exposed eastern range front. Marine deposition in the Vallecitos ended near the close of the Relizian; in contrast, marine conditions to the east in the San Joaquin basin persisted into the early Mohnian. A thick sequence of post-Luisian(.) lacustrine shales in the eastern Vallecitos suggests continued fold growth and increased isolation of the depocenter as a transpressional piggyback basin.

• Research Organization: Stanford Univ., CA
• OSTI ID: 6886515
• Report Number(s): CONF-8604187-
• Conference Information: Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Journal Volume: 70:4
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
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& Exploration
CALIFORNIA
DEPOSITION
FEDERAL REGION IX
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
NORTH AMERICA
RESERVOIR ROCK
SEDIMENTARY BASINS
SEDIMENTATION
USA