About This Item
- Full TextFull Text(subscription required)
- Pay-Per-View PurchasePay-Per-View
Purchase Options Explain
Share This Item
The AAPG/Datapages Combined Publications Database
Utah Geological Association
Abstract
Review of the Quaternary Geology of the Sevier and Black Rock Deserts
Abstract
The Sevier basin, a complex tectonic basin occupied by the Sevier and Black Rock Deserts, contains a thick succession of Tertiary sediments primarily of lacustrine origin. These include Oligocene evaporites and Miocene to Pliocene fine-grained deposits and limestone. A shallow lake or series of lakes apparently existed almost continuously in at least part of the basin from prior to 3 Ma until at least 758 ka. The stratigraphic record for the period from 758 ka to about 150 ka, however, is largely missing from the basin. Basalt flows that range in age from 0.8–1 Ma cap pedestals of fine-grained lake sediments and indicate topographic inversion and erosional removal of a vast quantity of lacustrine sediment from the basin floor caused by lowering of the threshold between the Sevier and Great Salt Lake basins. At Bishop ash time (758 ka) a fresh- to brackish-water lake in the Sevier basin probably overflowed northward to a shallow lake in the Great Salt Lake basin. Deposits of the Little Valley Lake cycle (about 150 ka) are exposed in a small area along the Sevier River near Delta, and during the last major (Bonneville) lake cycle (about 20–12 ka) numerous facies were deposited throughout the basin, including offshore marl, shorezone gravel and sand, and fine-grained deltaic units. Even the Bonneville deposits, however, have been eroded from most of the region. The last Pleistocene lake in the basin was Lake Gunnison (about 11–10 ka), which was followed by much smaller lake expansions in Sevier Lake during the Holocene.
Pay-Per-View Purchase Options
The article is available through a document delivery service. Explain these Purchase Options.
Watermarked PDF Document: $14 | |
Open PDF Document: $24 |