IMAGING THE RUBY MOUNTAINS CORE COMPLEX WITH AMBIENT NOISE TOMOGRAPHY

The Ruby Mountains Core Complex (RMCC) in northeastern Nevada is a well-studied example of a metamorphic core complex, yet many questions remain about its formation and deep structure. In June 2010, the Ruby Mountains Seismic Experiment was deployed as part of Earthscope's Flexible Array in order to collect new data that could help answer some of these questions. It consists of a 50-station broadband seismic array with dense station spacing of 5-10 km that is arranged in three crossing lines over the Ruby Range, one NNE-SSW transect along the axis of the range and two WNW-ESE transects that run from the Piñon Range in the west across the Ruby Mountains to the Cherry Creek Range in the east. Data acquisition for the project will last about two years. Here we present results from the first nine months of data. We use ambient noise tomography to make a velocity model of the area around the RMCC. We hope to distinguish mafic intrusions derived from the mantle from pre-existing felsic to intermediate crust, and to produce new map of the Moho. We will also look for changes in seismic velocity from north to south that reflect changes in the metamorphic grade of the core complex. Our ultimate goal is to provide new constraints on the structure of the RMCC in order to help differentiate between various models of core complex formation.