Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 3065

Lithic breccia and ignimbrite erupted during the collapse of Crater Lake Caldera, Oregon Lithic breccia and ignimbrite erupted during the collapse of Crater Lake Caldera, Oregon

The climactic eruption of Mount Mazama (6845 y.B.P.) vented a total of ∼50 km3 of compositionally zoned rhyodacitic to basaltic magma from: (a) a single vent as a Plinian pumice fall deposit and the overlying Wineglass Welded Tuff, and (b) ring vents as ignimbrite and coignimbrite lithic breccia accompanying the collapse of Crater Lake caldera. New field and grain-size data for the ring...
Authors
T. H. Druitt, C. R. Bacon

Deformation of poorly consolidated sediment during shallow emplacement of a basalt sill, Coso Range, California Deformation of poorly consolidated sediment during shallow emplacement of a basalt sill, Coso Range, California

A 150-m-long, wedge-shaped unit of folded and faulted marly siltstone crops out between undeformed sedimentary rocks on the north flank of the Coso Range, California. The several-meter-thick blunt end of this wedge abuts the north margin of a basaltic sill of comparable thickness. Chaotically deformed siltstone crops out locally at the margin of this sill, and at one locality breccia...
Authors
W. A. Duffield, C. R. Bacon, P.T. Delaney
Was this page helpful?