Neogene evolution of the Indian Wells Valley, east-central California

Abstract

The Indian Wells Valley located in east-central California has been an active sedimentary basin off and on throughoutTertiary time. During the Paleogene, the Indian Wells Valley was part of the Goler basin, and in the Miocene, the valley received volcaniclastic and terrigenous sediment correlated with rocks of the Ricardo Group. In the Pliocene, the Indian Wells Valley became the locus of deposition in a half graben formed by low-angle normal faulting along the eastern front of the Sierra Nevada. Two significant structural and tectonic changes are recorded in the stratigraphy of the Indian Wells Valley: one at the close of the Miocene and the second at the end of the Pliocene. The late Miocene transition occurred sometime between 7 and 5 Ma and resulted in the uplift of the nearby Sierra Nevada and the formation of a half graben. Transition from a regime of east-west extension to one dominated by transtensional dextral faulting occurred in the late Pliocene, marking a change in regional stress, the cause of which is, as yet, undocumented. Dextral strike-slip faulting dominates the modern structural setting and controls the sparse sedimentation in the valley. This pattern of extension followed by transtension appears to be part of a progression that began in Death Valley ca. 16 Ma and moved westward. Today the Indian Wells Valley accommodates a component of integrated transtensional shear and is part of the evolving margin between the North American and Pacific plates.

Strain transfer and partitioning between the Panamint Valley, Searles Valley, and Ash Hill fault zones, California

“…1). The onset of this transition occurred in late Miocene to Pleistocene time (Wernicke et al, 1988;Bellier and Zoback, 1995;Wernicke and Snow, 1998;Snow and Wernicke, 2000;Monastero et al, 2002). Active faulting in this area is well documented by seismic (e.g., Wallace, 1984) and global-positioning-system (GPS) studies (Dixon et al, 1995(Dixon et al, , 2000, as well as by geologic investigations (Burchfiel et al, 1987;Zhang et al, 1990;Klinger and Piety, 2001;Andrew, 2002).…”

Transtensional analyses of fault patterns and strain provinces of the Eastern California shear zone–Walker Lane on the eastern margin of the Sierra Nevada microplate, California and Nevada

“…Transtension moved into the Saline Valley -Hunter Mountain -Panamint Valley Fault system at , 3.7 Ma (Hodges et al 1989;Zhang et al 1990), and into Coso and Owens Valley at , 3.4 and 3.0 Ma, respectively Stockli et al 2003). This time also marks the end of significant uplift of the southern Sierra Nevada range front and from , 3 to 3.4 Ma to the present, the edge of the Sierra Nevada block has served as the boundary of transtensional deformation in the Walker Lane and northern ECSZ Monastero et al 2002).…”

“…In the northern ECSZ (from the Garlock Fault to Long Valley, Figure 1), the onset of oblique dextral shear on the Fish Lake Valley -Death Valley Fault system began 5 -6 Ma, coeval with the onset of uplift of the southern Sierra Nevada along the Sierra Nevada Frontal Fault Zone (Unruh 1991;Reheis and Sawyer 1997;Monastero et al 2002;Kamola et al 2005). From 5 to 6 Ma until , 3.7 Ma, dextral shear was accommodated by the Fish Lake Valley -Death Valley Fault system and faults of the westernmost Walker Lane to the north, including the Bettles Well-Petrified Springs and Benton Spring Fault Zones (Oldow et al 1994(Oldow et al , 2008.…”

“…Extension in the Death Valley area and the faults of the eastern Walker Lane began 12-16 Ma and moved westwards, followed by oblique shearing at 5-6 Ma (Oldow et al 1994;Serpa and Pavlis 1996;Surpless et al 2002). The ages and structural geology of the westernmost basins and structures adjacent to the eastern Sierra Nevada margin establish that present-day northwest-oblique deformation post-dates east -west Miocene -Pliocene extension in individual basins (Kamola and Walker 2000;Monastero et al 2002;Trexler and Cashman 2005). Transtension has migrated westwards through time, trailing extension, and the ECSZ -WL has collectively accommodated the relatively uniform motion of the Sierran microplate, with respect to stable North America (Atwater and Stock 1998;McQuarrie and Wernicke 2005).…”

Geologic Map of the Northern Lava Mountains and Summit Range, San Bernardino County, California

“…Several similar units occur on the north side of the Garlock fault that are bright white, well-bedded ash tuffs that we correlate to the Early Miocene Eagle Crags Volcanics and Cudahy Camp Formation. Monastero et al (2002) interpreted the presence of buried Cudahy Camp Formation in the same area of Teagle Wash from seismic data. Several of these tuffs occur in the Garlock fault zone, these tuffs are strongly oxidized to red colors.…”