Abstract: Timing of Tertiary Submarine Canyons and Marine Cycles of Deposition in Southern Sacramento Valley, California

A. A. Almgren

The Tertiary sedimentary rocks of the southern Sacramento Valley, California, include three marine cycles of deposition with similar development. Each cycle began with a marginal-marine to marine sandstone transgression followed by subsidence to bathyal depths and then a shoaling of varying degrees (at least of preservation). A fourth and last marine cycle began with shallow-marine deposition, but this soon gave way to marginal and nonmarine deposition.

Each cycle of deposition was preceded by a period of tectonism and erosion, and three of the cycles also were preceded by the cutting of a submarine canyon which subsequently was filled by marine sediment. The three submarine canyons are: (1) the "Martinez Channel," cut and filled in early to middle Paleocene time; (2) the "Meganos Channel," cut and filled in late Paleocene time; and (3) the "Markley Channel," cut in late Eocene (early Refugian) and filled in latest Eocene (late Refugian) to early Miocene time.

It is significant that the filling of each submarine channel precedes a new cycle of deposition. The timing of the development of these channels in relation to the cycles of deposition apparently is related directly to the tectonic activity of northern California and its borderland.

AAPG Search and Discovery Article #90972©1976 AAPG-SEPM Annual Convention and Exhibition, New Orleans, LA