Source-Area Dynamics Recorded in Pennsylvanian to Early Permian Keeler Canyon Formation, Death Valley-Owens Valley Region, California

Lyndon A. Yose, Robert P. Miller, Paul L. Heller

The middle to upper Keeler Canyon Formation exposed in east-central California is composed of up to 1,200 m of mixed-carbonate/siliciclastic gravity-flow deposits that accumulated in a basin inherited from the Antler foreland basin. Based on lithologic and facies associations and on paleocurrent data, this basinal succession is divisible into two distinct depositional sequences related to the evolution of two separate source areas.

The lower sequence (250-300 m thick) was deposited during the Desmoinesian to early Virgilian. These deposits lack channel and lobe sub-facies characteristics of the submarine fan model and are interpreted to have accumulated as a base-of-slope apron adjacent to a distally steepened carbonate ramp. Two types of sediment were supplied to this system including locally derived carbonate debris and craton-derived quartz silt. Mixture of both types of sediment were transported north-northwest within the basin indicating derivation from southeastern shelf.

The upper sequence (up to 800 m thick) ranges from the early Virgilian to Early Wolfcampian in age and contains numerous small-scale turbidite packages (<10 m thick), which may correspond to depositional lobes within a submarine fan system. The terrigenous sediment supplied to this system (in addition to locally derived carbonate debris) is composed of a distinct assemblage of coarse-grained quartz sand, detrital chert, and quartzarenite fragments. Paleocurrent indicators in this sequence are oriented south-southwest, directly opposing those of the lower sequence.

Contrasts in provenance and facies development between the lower and upper sequences indicate a major change in paleogeography during the deposition of the Keller Canyon Formation. Depositional patterns within the lower sequence are consistent with a southern carbonate shelf (Bird Spring Formation) attached to a cratonal source area (Supai Group). Depositional patterns within the upper sequence record the advancement of a carbonate shelf system into the basin from the northeast, which, based on lithologic associations, may be attached to an emergent remnant of the Antler belt.

AAPG Search and Discovery Article #91024©1989 AAPG Pacific Section, May 10-12, 1989, Palm Springs, California.