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Publications

Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center

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Attenuation of the Coast Range ophiolite by extensional faulting and nature of the Coast Range "thrust," California

The late Mesozoic Coast Range ophiolite and Great Valley sequence in California were juxtaposed against the Franciscan Complex during a long tectonic history that included imbricate thrust faulting, low‐angle detachment, and high‐angle reverse faulting. Many low‐angle faults previously mapped as thrusts invariably juxtapose younger over older rocks, suggesting a normal sense of offset. We infer th
Authors
A. S. Jayko, M. Clark Blake, Tekla Harms

Remagnetization of the Coast Range Ophiolite and Lower Part of the Great Valley Sequence in Northern California and Southwest Oregon

Overprinted magnetizations have been found at four localities in the Middle Jurassic Coast Range ophiolite and the overlying Upper Jurassic and Lower Cretaceous Great Valley sequence in northern California and at one locality in the partially correlative Lower Cretaceous Days Creek Formation in southwest Oregon. At Del Puerto Canyon, on the east side of the Diablo Range, a pilot study of the upper
Authors
L.S. Frei, M. Clark Blake

Correlation of early Cretaceous blueschists in Washington, Oregon and northern California

The protolith and metamorphic histories of Early Cretaceous blueschists that occur in Washington, Oregon, and California are remarkably similar. These blueschists are the Shuksan metamorphic suite of northwestern Washington, the Condrey Mountain schist of northern California and southern Oregon, and the Pickett Peak terrane of northern California and southwestern Oregon. We suggest that these bodi
Authors
E. H. Brown, M. C. Blake

Unconformity between Coast Range ophiolite and part of the lower Great Valley sequence, South Fork of Elder Creek, Tehama County, California

The South Fork of Elder Creek is located on private property about 6 mi (10 km) northwest of Paskenta, Calif. (Fig. 1). To visit this locality it is necessary to call Mr. Les Sutfin (916-824-4628) and arrange to pick up the key to the gate at his home in Corning. From the Paskenta Store, drive 3.3 mi (5.3 km) north on the Toomes Camp road to the locked gate on the north side of the road. From here
Authors
M. C. Blake, Jr., A. S. Jayko, D. L. Jones, B. W. Rogers

Selenium adsorption by goethite

The adsorption of Se by goethite was studied as a function of time (10 min–24 h), temperature (295.5 and 303.5 K), pH (4–11), particle concentration (3–300 mg/L), total Se concentration (0.02–5 × 10−5 M), oxidation state [Se(IV) and Se(VI)], and competing anion concentration [(anion)/(Se(IV) = 0.25 to 50 000] in order to assess the influence of these factors on Se mobility. The data indicate that
Authors
Laurie S. Balistrieri, T. T. Chao

Volcanism and massive sulfide formation at a sedimented spreading center, Escanaba Trough, Gorda Ridge, northeast Pacific Ocean

Seismic‐reflection profiles over the sediment‐filled Escanaba Trough at the southern Gorda Ridge reveal a series of volcanic centers that pierce the sediment. The volcanic edifices are 3 to 6 km in diameter and are spaced at 15 to 20 km intervals along the axis of the trough. The volcanic intrusions have uplifted the sediment as much as 100 m, and in places fresh basaltic flows are exposed at the
Authors
Janet L. Morton, Mark L. Holmes, Randolph A. Koski

Sediment-yield history of a small basin in southern Utah, 1937–1976: Implications for land management and geomorphology

Alluvium deposited in a reservoir from 1937 to 1976 records the sediment-yield history of a small (2.8 km2), high-relief basin in semiarid southern Utah. Stratification in the alluvium shows that sediment was deposited in the reservoir only 21 times in 38 yr, a runoff recurrence interval of 1.8 yr. Thus, on average, the particular combination of rainfall intensity, duration, and antecedent moistur
Authors
Richard Hereford

Overview of geomagnetism and paleomagnetism, 1983–1986

Michael Fuller, author of a similar overview four years ago, concluded that “...the next quadrennium promises to be a most interesting one, with plenty to keep us busy.” The 11 review papers that follow support his prediction; research in geomagnetism and paleomagnetism indeed has flourished over the last four years. In this brief overview, I will attempt to summarize what I perceive as important
Authors
Richard J. Blakely
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