Depositional model for submarine fan deposits of Vedder sandstone, eastern San Joaquin basin

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

OSTI ID:7152179

Dean, J S

The Vedder sandstone is an informal subsurface term applied collectively to a series of offlapping clastic wedges of late Oligocene through early Miocene age that subcrop beneath the basal Saucesian unconformity along the southeastern flank of the San Joaquin basin. Although the Vedder has generally been accepted as a shoreface to shallow-water shelf deposit, such an interpretation is inconsistent with the sandstone body geometry, vertical and lateral sequence architecture, and inferred paleobathymetry of foraminiferal assemblages for the interval over the greater part of the northwestern subcrop trend. The Vedder sandstone in that region represents deposition in a series of small submarine fans that coalesced at the base of a fault-controlled slope along the eastern margin of the Zemorrian San Joaquin basin. The Vedder fans exhibit a relatively broad inner fan apron composed of amalgamated, channel-fill deposits that pass quickly downdip into a highly variable midfan belt of channel-levee complexes. The outer fan is characterized by thick, sand-rich depositional lobes with a narrow outer fan fringe. Three periods of fan progradation are recognized in the Vedder interval, each corresponding to a relative sea level drop related to local tectonic pulses in the active forearc setting. A subsequent lowstand coincident with major uplift along the basin margin resulted in a regional unconformity that beheaded the Vedder fans and stripped off much of the equivalent slope and shelf facies. This unconformity juxtaposed the updip Vedder sandstones against an overlying transgressive sandstone, thus reducing the otherwise excellent stratigraphic trap geometries of the Vedder interval.

• Research Organization: RPI International, Inc., Boulder, CO
• OSTI ID: 7152179
• 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
Geology
& Exploration
CALIFORNIA
DEPOSITION
FEDERAL REGION IX
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOLOGIC TRAPS
MINERAL RESOURCES
NORTH AMERICA
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
USA