Abstract: Late Miocene Turbidite Deposition, Crocker Canyon Area, Southwest San Joaquin Valley, California

Susan M. Chandler, J. R. Bowersox, Ed Miller

The exposure of upper Miocene Stevens sandstones in Crocker Canyon previously has been described inadequately and correlated erroneously as Santa Margarita Formation. In this study, a 288 m section was measured. The lithologies and sedimentary structures are (from base to top): 98 m of interbedded distal G, C, and F facies (diatomaceous siltstone and sandstone); 132 m of transitional distal-proximal B/2, C, and D facies (diatomaceous siltstone and sandstone); and 58 m of proximal A/3, A/4, and B/2, and F and G facies (sandstone). The Crocker Canyon section represents a complex history of distal to proximal facies turbidite-basinal fan deposition in upper to middle bathyal depths during late-middle Mohnian time. In view of the depositional environment, the member relation of Stevens sandstones to the Monterey Shale, and the fact that the type Santa Margarita Formation overlies the Monterey Shale, the Stevens sandstones cannot be Santa Mar arita Formation.

AAPG Search and Discovery Article #90963©1978 AAPG/SEG/SEPM Pacific Section Meeting, Sacramento, California