RECEIVER FUNCTION IMAGING OF THE RUBY MOUNTAINS METAMORPHIC CORE COMPLEX

The Ruby Mountains Core Complex (RMCC), located in the Basin-and-Range region in northeastern Nevada, is a classic example of a metamorphic core complex. It has been well mapped at the surface, but more investigation of its deep structure is necessary to better constrain the role of ductile flow versus brittle deformation in its formation. To further this goal, an Earthscope Flexible Array project called the Ruby Mountains Seismic Experiment was deployed from 2010 to 2012 to study the deep crustal structure of the RMCC. Passive seismic stations were spaced 5-10 km and arranged in three crossing lines over the RMCC, one NNE-SSW transect along the axis of the range and two WNW-ESE transects that ran from the Piñon Range in the west across the Ruby Mountains to the Cherry Creek Range in the east. We used a common conversion point stacking of receiver functions to produce a profile of structural discontinuities beneath the RMCC. We also used H-k stacking of receiver functions to construct a new map of crustal thickness and variations in Vp/Vs ratios in the area around the core complex. Our results show a mostly flat Moho beneath the RMCC at around 30 km depth, with little observable structure in the mid-crust. In the future, we will combine the results of this receiver function study with a previous study using ambient noise tomography to produce a new velocity model of the RMCC.