A Caltech Library Service

Magnitude and Timing of Extreme Continental Extension, Central Death Valley Region, California

Niemi, N. A. and Wernicke, B. P. and Brady, R. J. and Saleeby, J. B. and Dunne, G. C. (1999) Magnitude and Timing of Extreme Continental Extension, Central Death Valley Region, California. In: Proceedings of Conference on Status of Geologic Research and Mapping, Death Valley National Park. U.S. Geological Survey open-file report. No.99-153. U.S. Geological Survey , Denver, CO, pp. 33-35.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


New geochronologic, stratigraphic, and sedimentologic data indicate extreme late Cenozoic extension across the central Death Valley region (fig. 9). ^(40)Ar/^(39)Ar geochronology of sanidine from tuffs intercalated with steeply tilted sediments along the eastern margin of the central Death Valley region, including sections near Chicago Pass and at Eagle Mountain, indicates deposition from approximately 15 to 11.7 Ma (fig. 10). Clasts of marble, orthoquartzite, fusilinid limestone, and leucogabbro are prominent at both locations. The only known source in the Death Valley region for this clast assemblage is in the southern Cotton wood Mountains, more than 100 km away on the western flank of the Death Valley region. U/Pb geochronology of baddeleyite confirms that leucogabbro clasts from both sections have the same igneous crystallization age (~180 Ma) as the leucogabbroic phase of the Hunter Mountain batholith, in the southern Cottonwood Mountains. The sediments include debris flows, flood deposits, and monolithic boulder beds of large leucogabbro clasts (>1 m), suggesting deposition in an alluvial fan setting. Sedimentary transport of these deposits is unlikely to have exceeded 20 km. Restoration of the Eagle Mountain and Chicago Valley deposits to a position just east of the southern Cotton wood Mountains results in approximate net translations of 80 km and 104 km, respectively, at an azimuth of N. 67° W. (fig. 11). This suggests overall extension magnitudes of at least 500 percent across the Death Valley region since 12 Ma, with strain rates that approached 10^(-14)/s during maximum extension. These results support previous reconstructions based on isopachs and Mesozoic structural features. (See, for example, Wernicke and others, 1988.)

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Wernicke, B. P.0000-0002-7659-8358
Additional Information:© 1999 USGS.
Series Name:U.S. Geological Survey open-file report
Issue or Number:99-153
Record Number:CaltechAUTHORS:20141021-134204811
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:50625
Deposited By: Tony Diaz
Deposited On:21 Oct 2014 21:29
Last Modified:03 Oct 2019 07:25

Repository Staff Only: item control page