Publications
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Paleomagnetic results from the Shasta Bally Plutonic Belt in the Klamath Mountains Province, northern California Paleomagnetic results from the Shasta Bally Plutonic Belt in the Klamath Mountains Province, northern California
Available paleomagnetic data show approximately 100° of clockwise rotation for Permian and Triassic strata of the Eastern Klamath terrane. Jurassic strata of this terrane are rotated approximately 60° clockwise, which is comparable to rotations reported for Jurassic plutons that occur elsewhere in the Klamath Mountains province. Paleomagnetic data obtained during the present study from...
Authors
Edward A. Mankinen, William P. Irwin, C. Sherman Gromme
Vitrinite reflectance and illite crystallinity, Franciscan central belt and Yolla Bolly terrane, northern California Vitrinite reflectance and illite crystallinity, Franciscan central belt and Yolla Bolly terrane, northern California
No abstract available.
Authors
M.B. Underwood, R.H. Strong, M.C. Blake
Metamorphic core complexes, Mesozoic ductile thrusts, and Cenozoic detachments: Old Woman Mountains: Chemehuevi Mountains transect, California and Arizona Metamorphic core complexes, Mesozoic ductile thrusts, and Cenozoic detachments: Old Woman Mountains: Chemehuevi Mountains transect, California and Arizona
No abstract available.
Authors
Keith A. Howard, B.E. John, C. F. Miller
Tectonostratigraphic terranes of the Croissilles Harbour region, South Island, New Zealand Tectonostratigraphic terranes of the Croissilles Harbour region, South Island, New Zealand
The boundary between Hokonui and Te Anau assemblages is flanked by a broad (10–20 km) zone of imbricated slabs of late Paleozoic and Mesozoic lithostratigraphic terranes. Five terranes are mapped, three of predominantly sedimentary character (Dun Mountain‐Maitai, Rai, Pelorus) are separated by two consisting of ophiolitic melange (Patuki, Croisilles). A regional stratigraphy is mapped...
Authors
C. A. Landis, M. Clark Blake
Unconformity between Coast Range ophiolite and part of the lower Great Valley sequence, South Fork of Elder Creek, Tehama County, California 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...
Authors
Blake, A. S. Jayko, D. L. Jones, B. W. Rogers
Petrology and K-Ar ages of the Misheguk igneous sequence, an allochthonous mafic and ultramafic complex, and its metamorphic aureole, western Brooks Range, Alaska Petrology and K-Ar ages of the Misheguk igneous sequence, an allochthonous mafic and ultramafic complex, and its metamorphic aureole, western Brooks Range, Alaska
No abstract available.
Authors
J.M. Boak, D. L. Turner, D.J. Henry, Thomas E. Moore, W. K. Wallace
Crustal extension along a rooted system of imbricate low-angle faults: Colorado River extensional corridor, California and Arizona Crustal extension along a rooted system of imbricate low-angle faults: Colorado River extensional corridor, California and Arizona
The upper 10 to 15 km of crystalline crust in the 100-km-wide Colorado River extensional corridor of mid-Tertiary age underwent extension along an imbricate system of gently dipping normal faults. Detachment faults cut gently down-section eastward in the direction of tectonic transport from a headwall breakaway, best expressed in the Old Woman Mountains, California. Successively higher...
Authors
Keith A. Howard, B.E. John
Comment and reply on "Correlation of the Peach Springs Tuff, a large-volume Miocene ignimbrite sheet in California and Arizona" Comment and reply on "Correlation of the Peach Springs Tuff, a large-volume Miocene ignimbrite sheet in California and Arizona"
No abstract available.
Authors
S.K. Mittwede, A. F. Glazner, Keith A. Howard, D. M. Miller
Lamoille Canyon nappe in the Ruby Mountains metamorphic core complex, Nevada Lamoille Canyon nappe in the Ruby Mountains metamorphic core complex, Nevada
No abstract available.
Authors
Keith A. Howard
In search of the Abrams post office, Trinity County In search of the Abrams post office, Trinity County
An understanding of earth history depends in part on stratigraphy, a division of geology in which the distinctive features of natural units or formations of layered rocks are studied and described and names are assigned to them. The procedures for describing and naming rock units in a uniform way are incorporated in documents known as stratigraphic codes. The North American Stratigraphic...
Authors
Marvin A. Lanphere, William P. Irwin
Thermal maturity of tectonostratigraphic terranes within the Franciscan Complex, California Thermal maturity of tectonostratigraphic terranes within the Franciscan Complex, California
Indicators of organic metamorphism provide valuable tools for analyzing the thermal history of tectonostratigraphic terranes. Paleotemperature estimates derived from vitrinite reflectance, for example, are more precise than values based upon inorganic mineral assemblages in low‐grade rocks. Isothermal geometries must be interpreted within the context of structural and stratigraphic data...
Authors
M.B. Underwood, M. Clark Blake, D. G. Howell
Attenuation of the Coast Range ophiolite by extensional faulting and nature of the Coast Range "thrust," California 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...
Authors
A. S. Jayko, M. Clark Blake, Tekla Harms