Depositional history of the Black Mountain conglomerate, Mohave County, Arizona: Sedimentary response to Miocene extension.

摘要

This study documents the Miocene depositional and extensional history for the area west of Wilson Ridge in the Black Mountains, northwestern Arizona. The field area, part of the Basin and Range province, lies within an area that experienced northward migration of intense volcanism several million years prior to significant regional extension. Extension propagated northward through the northern Colorado River extensional corridor to the Lake Mead area. Clastic sedimentary rocks in the basin are linked to the extension of the region.; Documentation of the basin fill was conducted with the aim of determining whether sedimentary clasts can be tied to lithologies that are exposed along Wilson Ridge and whether there is an unroofing sequence preserved within the basin. Stratigraphic sections from four locations were measured to capture the vertical succession of clastic and volcanic rocks and correlated to determine the lateral variability within the basin. Data collected from these sections included changes in bedding orientation, clast compositions, paleocurrent directions, and provenance. (Abstract shortened by UMI.)