An Analysis of Sedimentary Xenoliths: Ice Springs Volcanic Field, The Black Rock Desert, Utah

Kevin W. Silver, The College of Wooster

Abstract

Ice Springs, located on the eastern edge of the Basin and Range province in Utah, is a very recent basaltic volcanic field that is a part of a larger volcanic region known as the Black Rock Desert. This area is host to bimodal volcanism, which has been triggered by the east-west crustal extension that characterizes the Basin and Range province. Miter, one of the eruptive centers of Ice Springs, has erupted a large quantity of sedimentary xenoliths onto its slopes. If the stratigraphic origin of these xenoliths can be determined, then the general depths at which the magmas of Miter underwent fragmetation and became explosive could be estimated. These xenoliths have been documented and samples collected for lab analysis. Using thin section and X-ray diffractometer analyses, the lithologies of these xenoliths have been compared to the lithologic descriptions of the stratigraphic sequences underlying the Black Rock Desert basin. Through the process of elimination, the stratigraphic origin of the xenoliths of Miter has been determined to be shallow basin fill strata. However, the stratigraphic record of basin fill strata is still incomplete, thus only allowing a rough confinement of depth to be proposed at the present time. This maximum depth for fragmentation is three km.