Abstract: The Depositional Relationships between the Outcrops of the Santa Margarita Sandstone and Crocker Sandstone Members and the Subsurface Spellacy Sandstone Member, Monterey Formation, Midway-Sunset Oil Field, California

GREGORY, GLENN J., and DAVID H. STURM

In the Temblor Range along the southwest edge of the Midway-Sunset Oil Field, the Upper Miocene Santa Margarita Sandstone Member crops out as a series of nine northeast-trending sandy conglomeratic submarine-canyon fills within the Belridge Diatomite Member of the Monterey Formation. In the shallow subsurface the canyon fills with associated landslides and debris flows grade laterally northeastward into thick conglomerates and sandstones of the Spellacy Sandstone Member. The depositional morphology and grain size distribution is influenced by the conglomerate and sand rich flows and the intraslope synclines of the growing Midway fold system. The multiple channel submarine flows deposited most of their conglomerates within the synclines making northwest-southeast correlations difficult. Sandstones were deposited as they flowed across active folds and then turned in a northwest and/or southeast direction along the restricted Midway synclinal basin. Subsurface E-log correlations show that the Crocker Sandstone Member that crops out in the Midway syncline northwest of the oil field is a unit within the thick Spellacy Sandstone Member. The Crocker Sandstone Member pinches out onto the southwest flank of the Globe anticline just as the Spellacy Sandstone Member pinches out onto the southwest flank of the United and Buena Vista anticlines.

Search and Discovery Article #90945©1997 AAPG Pacific Section Meeting, Bakersfield, California