Review of paleomagnetic data from the Klamath Mountains, Blue Mountains, and Sierra Nevada; Implications for paleogeographic reconstructions

1990 ◽  
pp. 397-410 ◽  
Author(s):  
Edward A. Mankinen ◽  
William P. Irwin
Keyword(s):  
Sierra Nevada ◽  
Paleomagnetic Data ◽  
Klamath Mountains ◽  
Blue Mountains

Geodynamic implications of Devonian silicic arc magmatism in the Sierra Nevada and Klamath Mountains, California

Geology ◽  
1989 ◽  
Vol 17 (2) ◽  
pp. 177 ◽  
Author(s):  
O. Rouer ◽  
H. Lapierre ◽  
G. Mascle ◽  
C. Coulon ◽  
J. Albers
Keyword(s):  
Sierra Nevada ◽  
Arc Magmatism ◽  
Klamath Mountains

scholarly journals A crucial geologic test of Late Jurassic exotic collision versus endemic re-accretion in the Klamath Mountains Province, western United States, with implications for the assembly of western North America

2021 ◽  
Author(s):  
Todd A. LaMaskin ◽  
Jonathan A. Rivas ◽  
David L. Barbeau ◽  
Joshua J. Schwartz ◽  
John A. Russell ◽  
...  
Keyword(s):  
North America ◽  
Sierra Nevada ◽  
Continental Margin ◽  
North American ◽  
Detrital Zircon ◽  
Late Jurassic ◽  
North American Plate ◽  
Klamath Mountains ◽  
Clastic Rocks ◽  
Plate Margin

Differing interpretations of geophysical and geologic data have led to debate regarding continent-scale plate configuration, subduction polarity, and timing of collisional events on the western North American plate margin in pre–mid-Cretaceous time. One set of models involves collision and accretion of far-traveled “exotic” terranes against the continental margin along a west-dipping subduction zone, whereas a second set of models involves long-lived, east-dipping subduction under the continental margin and a fringing or “endemic” origin for many Mesozoic terranes on the western North American plate margin. Here, we present new detrital zircon U-Pb ages from clastic rocks of the Rattlesnake Creek and Western Klamath terranes in the Klamath Mountains of northern California and southern Oregon that provide a test of these contrasting models. Our data show that portions of the Rattlesnake Creek terrane cover sequence (Salt Creek assemblage) are no older than ca. 170–161 Ma (Middle–early Late Jurassic) and contain 62–83% Precambrian detrital zircon grains. Turbidite sandstone samples of the Galice Formation are no older than ca. 158–153 Ma (middle Late Jurassic) and contain 15–55% Precambrian detrital zircon grains. Based on a comparison of our data to published magmatic and detrital ages representing provenance scenarios predicted by the exotic and endemic models (a crucial geologic test), we show that our samples were likely sourced from the previously accreted, older terranes of the Klamath Mountains and Sierra Nevada, as well as active-arc sources, with some degree of contribution from recycled sources in the continental interior. Our observations are inconsistent with paleogeographic reconstructions that are based on exotic, intra-oceanic arcs formed far offshore of North America. In contrast, the incorporation of recycled detritus from older terranes of the Klamath Mountains and Sierra Nevada, as well as North America, into the Rattlesnake Creek and Western Klamath terranes prior to Late Jurassic deformation adds substantial support to endemic models. Our results suggest that during long-lived, east-dipping subduction, the opening and subsequent closing of the marginal Galice/Josephine basin occurred as a result of in situ extension and subsequent contraction. Our results show that tectonic models invoking exotic, intra-oceanic archipelagos composed of Cordilleran arc terranes fail a crucial geologic test of the terranes’ proposed exotic origin and support the occurrence of east-dipping, pre–mid-Cretaceous subduction beneath the North American continental margin.

Cretaceous sedimentary blanketing and tectonic rejuvenation in the Western Klamath moutains: Insights from thermochronology

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Geoffrey Batt ◽  
Gregory Harper ◽  
Matthew Heizler ◽  
Mary Roden-Tice
Keyword(s):  
Sierra Nevada ◽  
Early Cretaceous ◽  
Late Cretaceous ◽  
Sedimentary Basin ◽  
Local Maximum ◽  
Normal Faulting ◽  
Klamath Mountains ◽  
Maximum Thickness

AbstractWe present new thermochronometric analyses of 4 samples from the Western Klamath mountains in California and Oregon, together with a re-evaluation of available geological constraint from a thermo-tectonic perspective. Early Cretaceous cooling of basement samples is seen to reflect significant exhumation by normal faulting, linked to the Separation Episode during which the Klamah region was rifted away from the formerly contiguous Sierra Nevada block. Syn-faulting sedimentation and subsequent Early Cretaceous re-heating of samples establishes the former continuity of scattered Hornbrook Formation remnants as a significant sedimentary basin spanning the Klamath region, with local maximum thickness of at least 5 km. This basin experienced significant inversion during early Cordilleran development around 110–120 Ma, with further unrooting and almost complete eversion in the Late Cretaceous, associated with Laramide uplift of the region.

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