Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2383
Geophysics: A reversal of geomagnetic polarity
The detailed behaviour of the geomagnetic field during reversals is documented by palaeomagnetists to constrain models of the geomagnetic dynamo. Reversals are studied by measuring the magnetic remanence preserved in rocks to obtain both the direction and intensity of the ancient magnetic field.
Authors
Edward A. Mankinen
Paleomagnetism and K-Ar ages of volcanic rocks from Long Valley caldera, California
Paleomagnetic measurements and K‐Ar age determinations on volcanic rocks from Long Valley caldera, California, have enabled further refinement of eruptive activity within this large silicic volcanic center. K‐Ar age determinations show that postcaldera volcanic eruptions began 0.73 m.y. ago and continued periodically until about 50,000 years ago. The eruptions were not temporally random but tended
Authors
Edward A. Mankinen, C. Sherman Grommé, G. Brent Dalrymple, Marvin A. Lanphere, Roy A. Bailey
Southern hemisphere origin of the Cretaceous Laytonville Limestone of California
New paleomagnetic, paleontologic, and stratigraphic data from outcrops of the Laytonville Limestone (101 to 88 million years old) support a Southern Hemisphere orgin. A paleomagnetic megaconglomerate test is statistically significant and suggests magnetization at 14?? ?? 5?? south, predating Late Cretaceous to Eocene (70 to 50 million years ago) accretion. Rapid Kula plate movement or the existenc
Authors
J.A. Tarduno, M. McWilliams, W.V. Sliter, H. E. Cook, M. C. Blake, I. Premoli-Silva
Preliminary geologic map of Santa Cruz County, California
No abstract available.
Authors
Earl E. Brabb
Map showing the status of landslide inventory and susceptibility mapping in California
No abstract available.
Authors
Fred Taylor, E. E. Brabb
Age and tectonics of plutonic belts in accreted terranes of the Klamath Mountains, California and Oregon
No abstract available.
Authors
W. P. Irwin
Equivalent radiolarian ages from ophiolitic terranes of Cyprus and Oman
Radiolarian biostratigraphy shows that umberiferous strata overlying the Troodos ophiolite in Cyprus are Turonian in age and are thus essentially contemporaneous with similar strata that overlie the Samail ophiolite in Oman. However, this radiolarian age is markedly older than Campanian isotopic ages measured on the underlying rocks of the Troodos ophiolite. The revised age for the umbers indicate
Authors
Charles D. Blome, William P. Irwin
Tectonostratigraphic terranes of northern California
No abstract available.
Authors
M. Clark Blake, A. S. Jayko, R. J. McLaughlin
Tectonostratigraphic terranes in southwest Oregon
No abstract available.
Authors
M. C. Blake, Jr., D.E. Engebretson, A. S. Jayko, J. L. Jones
Stratigraphy and tectonic significance of the Mesozoic tectonostratigraphic terranes of the Vizcaino Peninsula, Baja California Sur, Mexico
No abstract available.
Authors
Thomas E. Moore