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Full-Text Articles in Physical Sciences and Mathematics

Geochemistry Of The Great Valley Group: An Integrated Provenance Record, Kathleen Surpless Dec 2014

Geochemistry Of The Great Valley Group: An Integrated Provenance Record, Kathleen Surpless

Kathleen D. Surpless

Sedimentary geochemistry of fine-grained strata of the Great Valley Group (GVG) in California documents a provenance signal that may better represent unstable, mafic minerals and volcanic clasts within sediment source regions than the provenance signal documented in the petrofacies and detrital zircon analysis of coarser sedimentary fractions. Geochemistry of the GVG provides an overall provenance framework within which to interpret sandstone petrofacies and detrital zircon age signatures. The geochemical signature for all Sacramento Valley samples records an overall continental arc source, with significant variation but no clear spatial or temporal trends, indicating that the geochemical provenance signal remained relatively consistent …


Lithofacies Control In Detrital Zircon Provenance Studies: Insights From The Cretaceous Methow Basin, Southern Canadian Cordillera, Kathleen Surpless, J. Mahoney, Joseph Wooden, Michael Mcwilliams Dec 2014

Lithofacies Control In Detrital Zircon Provenance Studies: Insights From The Cretaceous Methow Basin, Southern Canadian Cordillera, Kathleen Surpless, J. Mahoney, Joseph Wooden, Michael Mcwilliams

Kathleen D. Surpless

High-frequency sampling for detrital zircon analysis can provide a detailed record of fine-scale basin evolution by revealing the temporal and spatial variability of detrital zircon ages within clastic sedimentary successions. This investigation employed detailed sampling of two sedimentary successions in the Methow/Methow-Tyaughton basin of the southern Canadian Cordillera to characterize the heterogeneity of detrital zircon signatures within single lithofacies and assess the applicability of detrital zircon analysis in distinguishing fine-scale provenance changes not apparent in lithologic analysis of the strata. The Methow/Methow-Tyaughton basin contains two distinct stratigraphic sequences of middle Albian to Santonian clastic sedimentary rocks: submarine-fan deposits of the …


Understanding A Critical Basinal Link In Cretaceous Cordilleran Paleogeography: Detailed Provenance Of The Hornbrook Formation, Oregon And California, Kathleen Surpless, Emily Beverly Dec 2014

Understanding A Critical Basinal Link In Cretaceous Cordilleran Paleogeography: Detailed Provenance Of The Hornbrook Formation, Oregon And California, Kathleen Surpless, Emily Beverly

Kathleen D. Surpless

The Hornbrook Formation is a Cretaceous overlap assemblage that rests unconformably on accreted terranes and plutons of the Klamath Mountains in southern Oregon and northern California. The combined results of sandstone petrography, detrital zircon U-Pb age and Hf isotopic systematics, and whole-rock Nd analysis document an abrupt change in sediment sources for the Hornbrook Formation during the Late Cretaceous. The lower members of the Hornbrook Formation record provenance in the Klamath Mountains and the Sierran Foothills belt that is characterized by detrital zircon age distributions with large Jurassic and Early Cretaceous peaks (170-130 Ma) and positive zircon Hf and whole-rock …


Evolution And Stratigraphic Architecture Of Marine Slope Gully Complexes: Monterey Formation (Miocene), Gaviota Beach, California, Kathleen Surpless, Richard Ward, Stephan Graham Dec 2014

Evolution And Stratigraphic Architecture Of Marine Slope Gully Complexes: Monterey Formation (Miocene), Gaviota Beach, California, Kathleen Surpless, Richard Ward, Stephan Graham

Kathleen D. Surpless

Three small headlands in the sea cliffs west of Gaviota Beach, California, are the remnant fill of three discrete submarine gullies incised into the late Miocene submarine slope environment. These promontories provide excellent, three-dimensional exposure of the gully fill in outcrop, permitting documentation of their complex internal stratigraphic architecture. Detailed study of these exposures elucidates the sedimentologic processes that occur in the filling of slope gullies, guides interpretation of the acoustic records of otherwise unsampled modern gully systems on continental slopes, and provides insight into the heterogeneity that may characterize slope gully petroleum reservoirs. We develop a comprehensive facies scheme …


East-Derived Strata In The Methow Basin Record Rapid Mid-Cretaceous Uplift Of The Southern Coast Mountains Batholith, Kathleen Surpless, Zachary Sickmann, Trevor Koplitz Dec 2014

East-Derived Strata In The Methow Basin Record Rapid Mid-Cretaceous Uplift Of The Southern Coast Mountains Batholith, Kathleen Surpless, Zachary Sickmann, Trevor Koplitz

Kathleen D. Surpless

The Jurassic–Cretaceous Methow basin of northern Washington State and southern British Columbia forms an overlap sequence linking several small tectonostratigraphic terranes. Sandstone petrography, sandstone and mudrock geochemistry, and detrital zircon U–Pb age and Hf analysis of mid-Cretaceous, east-derived Methow strata together document a remarkably uniform provenance signature that suggests proximal, abundant, and unchanging sediment sources throughout deposition. The eastern belt of the Coast Mountains batholith, intruded into Stikine and related inboard terranes of the Intermontane superterrane, along with Jurassic and Cretaceous plutons of the westernmost Okanogan Range, provide the best match to the provenance signature of east-derived sediment in the …