Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 1155

Quickly erupted volcanic sections of the Steens Basalt, Columbia River Basalt Group: Secular variation, tectonic rotation, and the Steens Mountain reversal Quickly erupted volcanic sections of the Steens Basalt, Columbia River Basalt Group: Secular variation, tectonic rotation, and the Steens Mountain reversal

The Steens Basalt, now considered part of the Columbia River Basalt Group (CRBG), contains the earliest eruptions of this magmatic episode. Lava flows of the Steens Basalt cover about 50,000 km2 of the Oregon Plateau in sections up to 1000 m thick. The large number of continuously exposed, quickly erupted lava flows (some sections contain over 200 flows) allows for small loops in the...
Authors
Nicholas A. Jarboe, Robert S. Coe, Paul R. Renne, Jonathan M. G. Glen, Edward A. Mankinen

Stratigraphy of Colorado River deposits in lower Mohave Valley, Arizona and California Stratigraphy of Colorado River deposits in lower Mohave Valley, Arizona and California

Deposits in lower Mohave Valley and upper Topock Gorge near Topock, Arizona and Park Moabi, California record a succession of depositional and erosional events since late Miocene time that relate to the development of the Colorado River. Upper Miocene alluvial fans were deposited toward a depocenter east of the present valley bottom, indicating there was no valley outlet then through the...
Authors
Keith A. Howard, D.V. Malmon

Wild, scenic and rapid trip down the Colorado River trough: Desert Symposium field trip Wild, scenic and rapid trip down the Colorado River trough: Desert Symposium field trip

This rapid trip will explore wild fluvial and tectonic events resulting in scenic and rugged topography. The extreme differences in elevation caused valleys to be choked by alluvium and incised by the Colorado River drainage system.
Authors
R. E. Reynolds, J. Faulds, P.K. House, Keith A. Howard, Daniel V. Malmon, C. F. Miller, P. A. Pearthree

Overview: The Chemehuevi Formation along the lower Colorado River Overview: The Chemehuevi Formation along the lower Colorado River

A distinctive set of fine-grained deposits occurs throughout the lower Colorado River Valley, extending from just below the mouth of Grand Canyon to well into the river delta below Yuma, AZ (Figure 1), an along-channel distance of over 700 km. Upstream of Parker, Arizona, the deposits consist of scattered erosional remnants up to 150 m above the modern floodplain. Below Parker, they...
Authors
Daniel V. Malmon, Keith A. Howard

Formation of tectonic peperites from alkaline magmas intruded into wet sediments in the Beiya area, western Yunnan, China Formation of tectonic peperites from alkaline magmas intruded into wet sediments in the Beiya area, western Yunnan, China

Tertiary (3.78 Ma to 3.65 Ma) biotite-K-feldspar porphyritic bodies intrude Tertiary, poorly consolidated lacustrine sedimentary rocks in the Beiya mineral district in southwestern China. The intrusives are characterized by a microcrystalline and vitreous-cryptocrystalline groundmass, by replacement of some tabular K-feldspar phenocrysts with microcrystalline chlorite and calcite, and by...
Authors
Xing-Wang Xu, Xin-Ping Cai, Jia-You Zhong, Bao-Chang Song, Stephen G. Peters

Fault locking, block rotation and crustal deformation in the Pacific Northwest Fault locking, block rotation and crustal deformation in the Pacific Northwest

We interpret Global Positioning System (GPS) measurements in the northwestern United States and adjacent parts of western Canada to describe relative motions of crustal blocks, locking on faults and permanent deformation associated with convergence between the Juan de Fuca and North American plates. To estimate angular velocities of the oceanic Juan de Fuca and Explorer plates and...
Authors
Robert McCaffrey, Anthony I. Qamar, Robert W. King, Ray E. Wells, G. Khazaradze, C.A. Williams, C.W. Stevens, J.J. Vollick, P.C. Zwick

Regional Fluid Flow and Basin Modeling in Northern Alaska Regional Fluid Flow and Basin Modeling in Northern Alaska

The foothills of the Brooks Range contain an enormous accumulation of zinc (Zn) in the form of zinc sulfide and barium (Ba) in the form of barite in Carboniferous shale, chert, and mudstone. Most of the resources and reserves of Zn occur in the Red Dog deposit and others in the Red Dog district; these resources and reserves surpass those of most deposits worldwide in terms of size and...
Authors
Robert A. Ayuso, Robert Burruss, Julie A. Dumoulin, Garth E. Graham, Anita G. Harris, Craig A. Johnson, Karen D. Kelley, David L. Leach, Paul G. Lillis, Erin E. Marsh, Thomas E. Moore, Christopher J. Potter, John F. Slack
Was this page helpful?