Depositional Environments of Lower Mississippian Tin Mountain Limestone, Death Valley Region, California

Gregory R. Albright

The Lower Mississippian Tin Mountain Limestone records probable sublittoral carbonate sedimentation in an embryonic Antler foreland basin. Lithofacies include (1) thin-bedded skeletal mudstone/wackestone with Chondrites, (2) skeletal wackestone and packstone with common to abundant whole and fragmented rugose and tabulate corals, brachiopods, and crinoids, (3) cross-bedded crinoidal grainstone, and (4) medium to thick-bedded featureless mudstone. Preliminary data suggest that late Famennian regression gave way to an early Kinderhookian transgression. Initial carbonate sedimentation took place in a slightly northeast-southwest-trending shallow trough.

Famennian sea level fluctuations produced a rhythmic succession of nearshore sandstones and subtidal algal limestones at the close of the Devonian. This was followed by an early Kinderhookian sea level rise, the probable result of initial foreland basin development. Tin Mountain carbonate sediments were deposited in a shallowly inclined trough that deepened to the southwest. The Tin Mountain trough was sandwiched between platform carbonates (Dawn Member of the Monte Cristo Formation) to the southeast and siliciclastics (Perdido Formation) to the northwest.

Deposition of Tin Mountain carbonates began in a shallow but sublittoral setting. This setting is represented by thin-bedded, bioturbated skeletal mudstones/wackestones interbedded with very thin argillaceous limestones to calcareous shales and a few crinoidal packstone beds. Deepening water led to the deposition of cherty mudstones/wackestones and increasing numbers of cross-bedded crinoidal packstones/grainstones. In some localities, crinoid shoals developed. As subsidence outpaced carbonate production, quiet-water sediments, represented by medium to thick-bedded black featureless mudstone, were deposited throughout the region. The end of Tin Mountain deposition is marked by the influx of clastic sediment shed from the Antler highlands to the northwest.

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