Sediment provenance and dispersal of Neogene–Quaternary strata of the southeastern San Joaquin Basin and its transition into the southern Sierra Nevada, California

Abstract

We have studied detrital-zircon U-Pb age spectra and conglomerate clast populations from Neogene-Quaternary siliciclastic and volcaniclastic strata of the southeastern San Joaquin Basin, as well as a fault-controlled Neogene basin that formed across the southernmost Sierra Nevada; we call this basin the Walker graben. The age spectra of the detrital-zircon populations are compared to a large basement zircon age data set that is organized into age populations based on major drainage basin geometry of the southern Sierra Nevada and adjacent ranges. We find a direct sediment provenance and dispersal link for much of the Neogene between the Walker graben and the southeastern San Joaquin Basin. In early to middle Miocene time, this link was accented by the delivery of volcaniclastic materials into the southeastern Basin margin from the Cache Peak volcanic center that was nested within the Walker graben. In late middle Miocene through early Pleistocene time, this linkage was maintained by a major fluvial system that we call the Caliente River, whose lower trunk was structurally controlled by growth faults along the Edison graben, which breached the western wall of the Walker graben. The Caliente River redistributed into the southeastern San Joaquin Basin much of the ~2 km of volcaniclastic and siliciclastic strata that filled the Walker graben. This sediment redistribution was forced by a regional topographic gradient that developed in response to uplift along the eastern Sierra escarpment system. The Caliente River built a fluvial-deltaic fan system that prograded northwestward across the lower trunk of the Kern River and thereby deflected the Kern drainage flux of sediment into the Basin edge northward. In mainly late Miocene time, turbidites generated primarily off the Caliente River delta front built the Stevens submarine fan system of the southeastern and central areas of the San Joaquin Basin. In late Quaternary time, 1-1.8 km of Caliente River-built strata were eroded as an epeirogenic uplift that we call the Kern arch emerged along the southeastern Basin margin, in response to underlying mantle lithosphere removal. The sediment that was eroded off the arch was redistributed mainly into the Maricopa and Tulare sub-basins that are located to the southwest and northwest, respectively, of the arch.

The southern Sierra Nevada pediment, central California

“…1). Analogous to the stratigraphic relationship at the northern end of the pediment, Cenozoic strata of the Kern Arch are Eocene and younger, with the basal Walker Formation, containing a 40.1 ± 0.3 Ma tuff, deposited nonconformably on deeply weathered Sierran basement (Saleeby et al, 2016;Fig. 3A and 3C).…”

“…The nearest published U-Pb zircon age is from a 102 Ma quartz diorite a few kilometers to the east (Lackey et al, 2005;Saleeby and Sharp, 1980). A few kilometers south of this location along the White River, a 40.1 ± 0.3 Ma tuff sits on deeply weathered basement (Laser Abla tion ICP-MS zircon U-Pb from Saleeby et al [2016]). The mean Z-He age from sample 11SS1 is 85 ± 5 Ma (1 s.e., n = 4), and the mean Ap-He age is 66 ± 4 Ma (1 s.e., n = 7), with eU ranging from 13 ppm to 38 ppm.…”

“…85 Ma, after which slow cooling to surface conditions occurred at a rate of roughly 70 m/m.y. until deposition of the overlying tuff at 40.1 ± 0.3 Ma (Saleeby et al, 2016).…”

Geomorphic constraints on the incision history of the lower Kern River, southern Sierra Nevada, California

“…Partially to completely reset (U-Th)/He ages and inverse thermokinematic modeling suggest that subsidence and sedimentation occurred between 6 Ma and 1 Ma and was immediately followed by rapid exhumation (Cecil et al, 2014). Focused exhumation within the Kern arch resulted in partitioning of sedimentation in the southern San Joaquin Basin, where erosional unroofing redistributed sediment to the west, south, and north (Saleeby et al, 2012(Saleeby et al, , 2013(Saleeby et al, , 2016. North of the Kern arch, thermochronometric, geomorphologic, and geodetic constraints indicate that the Tulare sub-basin has experienced continuous subsidence to present (Stock et al, 2005;Mahéo et al, 2009;Saleeby et al, 2013Saleeby et al, , 2016Cecil et al, 2014).…”

Spatial Patterns of Chemical Weathering at the Basal Tertiary Nonconformity in California from Multispectral and Hyperspectral Optical Remote Sensing

“…exposed as the southern Sierra Nevada bedrock pediment which extends southward to the foothills near Bakersfield where it is overlain by Eocene volcanic rocks and sediments of the Walker Formation [2,4,26]. In the southernmost Sierra Nevada and El Paso Mountains, the base of the Tertiary section is overlain by the Witnet and Goler Formations, which are Paleocene and Eocene in age [22,[27][28][29][30][31].…”