UPLIFT IN THE SIERRA NEVADA: EXTENSIVE GEOLOGIC FIELD EVIDENCE THROUGHOUT THE RANGE SUPPORTS MAJOR LATE CRETACEOUS UPLIFT PLUS MAJOR INCISION INTO THE EOCENE

2020 ◽  
Author(s):  
Jeffrey P. Schaffer ◽  
◽  
William A. Peppin ◽  
Daniel P. Miggins
Keyword(s):  
Sierra Nevada ◽  
Late Cretaceous ◽  
Field Evidence

scholarly journals Trachyandesite of Kennedy Table, its vent complex, and post−9.3 Ma uplift of the central Sierra Nevada: Comment

2021 ◽  
Author(s):  
Emmanuel Gabet
Keyword(s):  
Lava Flow ◽  
Sierra Nevada ◽  
Volcanic Rocks ◽  
Rigid Block ◽  
Field Evidence ◽  
San Joaquin River ◽  
Table Mountains

Hildreth et al. (2021) analyzed a set of table mountains near the San Joaquin River that are capped by a 9.3 Ma trachyandesite lava flow and concluded that, since the deposition of the volcanic rocks, the table mountains have been tilted 1.07° due to uplift of the central Sierra Nevada. While Gabet (2014) suggested that, under a limited set of conditions, the size of fluvial gravels under the table mountains would support the hypothesis of postdepositional uplift, the authors claimed that their evidence is more definitive. In addition, the authors proposed that the central Sierra Nevada tilted as a rigid block. However, their analyses rely on inferences and assumptions that are not supported by field evidence.

Tectonic evolution of the central California margin as reflected by detrital zircon composition in the Mount Diablo region

2021 ◽  
Author(s):  
Jared T. Gooley ◽  
Marty Grove ◽  
Stephan A. Graham
Keyword(s):  
Sierra Nevada ◽  
Late Cretaceous ◽  
Late Miocene ◽  
Detrital Zircon ◽  
Middle Eocene ◽  
Forearc Basin ◽  
Zircon Age ◽  
Central California ◽  
Sierra Nevada Batholith ◽  
Early Paleogene

ABSTRACT The Mount Diablo region has been located within a hypothesized persistent corridor for clastic sediment delivery to the central California continental margin over the past ~100 m.y. In this paper, we present new detrital zircon U-Pb geochronology and integrate it with previously established geologic and sedimentologic relationships to document how Late Cretaceous through Cenozoic trends in sandstone composition varied through time in response to changing tectonic environments and paleogeography. Petrographic composition and detrital zircon age distributions of Great Valley forearc stratigraphy demonstrate a transition from axial drainage of the Klamath Mountains to a dominantly transverse Sierra Nevada plutonic source throughout Late Cretaceous–early Paleogene time. The abrupt presence of significant pre-Permian and Late Cretaceous–early Paleogene zircon age components suggests an addition of extraregional sediment derived from the Idaho batholith region and Challis volcanic field into the northern forearc basin by early–middle Eocene time as a result of continental extension and unroofing. New data from the Upper Cenozoic strata in the East Bay region show a punctuated voluminous influx (>30%) of middle Eocene–Miocene detrital zircon age populations that corresponds with westward migration and cessation of silicic ignimbrite eruptions in the Nevada caldera belt (ca. 43–40, 26–23 Ma). Delivery of extraregional sediment to central California diminished by early Miocene time as renewed erosion of the Sierra Nevada batholith and recycling of forearc strata were increasingly replaced by middle–late Miocene andesitic arc–derived sediment that was sourced from Ancestral Cascade volcanism (ca. 15–10 Ma) in the northern Sierra Nevada. Conversely, Cenozoic detrital zircon age distributions representative of the Mesozoic Sierra Nevada batholith and radiolarian chert and blueschist-facies lithics reflect sediment eroded from locally exhumed Mesozoic subduction complex and forearc basin strata. Intermingling of eastern- and western-derived provenance sources is consistent with uplift of the Coast Ranges and reversal of sediment transport associated with the late Miocene transpressive deformation along the Hayward and Calaveras faults. These provenance trends demonstrate a reorganization and expansion of the western continental drainage catchment in the California forearc during the late transition to flat-slab subduction of the Farallon plate, subsequent volcanism, and southwestward migration of the paleodrainage divide during slab rollback, and ultimately the cessation of convergent margin tectonics and initiation of the continental transform margin in north-central California.

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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