Marine Rocks in Nonmarine Miocene Caliente Formation, Northern Cuyama Badlands, Ventura County, California
The lower portion of the Caliente Formation in western Ballinger Canyon represents previously unrecognized coastal-marine deposits. These are conformably underlain by marine rocks of the Vaqueros Formation and conformably overlain by upper delta-plain fluvial rocks of the Caliente Formation.
Five lithosomes within the lower 152 m of the Caliente Formation represent shoreface, foreshore, backshore, marsh, and coastal-lagoon deposits. Lower shoreface deposits consist of medium to coarse-grained, structureless to finely laminated, feldspathic sandstone that contains abraded oysters. Overlying these are upper shoreface deposits consisting of interbedded pebble to cobble conglomerate and oyster-bearing medium to coarse-grained sandstone. These are overlain by foreshore and backshore deposits consisting of structureless to finely laminated, medium to fine-grained clayey sandstone. Above the backshore deposits are cyclic variegated red and green claystone and interbedded limestone deposited in coastal marshes and lagoons. Marine fossils include rare arenaceous foraminifera in the claystone and the foraminiferan Eponides sp. with abundant ostracoda in the limestone. The limestone beds consist of two depositional facies (pellet lime wackestone and pellet lime mudstone) and one diagenetic facies (crystalline limestone). Geochemical analyses of the Caliente limestone are typical of lagoonal marine limestone stabilized by freshwater diagenesis. Above the lagoonal limestone beds, marsh claystone grades rapidly into >850 m of interbedded upper d lta plain fluvial conglomerate, sandstone, and siltstone characteristic of the nonmarine part of the Caliente Formation.
Early reports on the Cuyama Badlands region indicated that the Vaqueros Formation was a deep-marine deposit in direct conformable contact with the overlying nonmarine Caliente Formation. Recognition of the above shallow-marine gradational sequence between these strata resolves this enigma.
AAPG Search and Discovery Article #91024©1989 AAPG Pacific Section, May 10-12, 1989, Palm Springs, California.