Abstract Title: Investigating the lithosphere in the Great Basin

Abstract Author(s): Catherine M. Snelson (Geoscience Department, University of 
Nevada Las Vegas)
 

Abstract: Mapping the continental lithosphere is one of the primary goals of 
Earthscope.  Therefore, it is necessary to acquire seismic reflection and 
refraction data to tie the teleseismic and geologic results together.  In 
Nevada, generally, there are very few high resolution crustal scale refraction 
profiles.  Most recently, crustal-scale profiles in both southern and northern 
Nevada have been acquired (Snelson et al., 2003; Louie et al., in review).  
These types of studies are proving that there is a need to conduct further 
active source crustal-scale profiles across various geologic targets in Nevada. 
 These studies will not only map out the basins, which are of high seismic 
risk, but also define and refine structures that have been previously 
identified by previous authors (e.g., Holbrook et al., 1991).  Identifying deep 
reflection bright spots, basin thicknesses, crustal roots, and mantle ÔdripsÕ 
are some of the scientific questions that could be addressed using active 
source seismology in conjunction with other geophysical and geologic studies.  
Integration of these types of data could lead a better understanding of the 
tectonic framework of the Basin and Range as well as a better understanding 
about the rheology of the lithosphere.  The recent studies in the Rocky 
Mountains (CD-ROM) have shown that integration of these various results are 
possible at the lithospheric scale as well as recent work in southern Nevada to 
characterize the Las Vegas area for seismic hazards, which are potential models 
of collaboration for the GreatBREAK working group.

References:
Holbrook, W. S., R. D. Catchings, and C. M. Jarchow, 1991, Origin of deep 
crustal reflections: Implications of coincident seismic refraction and 
reflection data in Nevada, Geology, v 19, p 175-179.

Louie, J. N., W. Thelen, S. B., Smith, J. B. Scott, M. Clark, and S. 
Pullammanappallil, in review, The northern Walker Lane refraction experiment: 
Pn arrivals and the northern Sierra Nevada root, Tectonophysics, 
http://www.seismo.unr.edu/ftp/pub/louie/geothermal/walker.html.

Snelson, C. M., Sandru, J., McEwan, D. J., Hirsch, A., Zaragoza, S. A., Draa, 
A., Hanson, A. D., Kaip, G., Harder, S. H., Azevedo, S., McKibben, W., Rodgers, 
A., Lewis, J. P., Smith, D., Rock, D., and McCallen, D., 2003, Preliminary 
Results From SILVVER Õ03 Ð Seismic Investigations of the Las Vegas Valley: 
Evaluating Risk, EOS Trans. AGU, 84(46), Fall Meet. Suppl., Abstract S11D-0325.