
%0 Journal Article
%A Peacock, Jared R. 
%A Denton, Kevin M. 
%A Ponce, David A. 
%T Magnetotelluric Imaging of a Carbonatite Terrane in the Southeast Mojave Desert, California and Nevada
%J ASEG Extended Abstracts
%D 2016/08/24
%V 2016
%N 1
%P 1-5
%K 
%R https://doi.org/10.1071/ASEG2016AB148
%U https://www.publish.csiro.au/paper/ASEG2016AB148 
%X The southeast Mojave Desert hosts one of the world&#x2019;s largest rare earth element (REE) deposits at Mountain Pass, California. Although surface geology has been studied, a full understanding of the carbonatite and associated intrusive suite complex requires subsurface geophysical characterization. In this study, a combination of geophysical methods, including magnetotelluric (MT), magnetics, and gravity are used to create a two-dimensional (2D) geophysical model to a depth of about 10 km. An electrically conductive body is found 2&#x2013;3 km below and west of the deposit that is associated with a magnetic high that could be connected to a deeper (10 km) conductive body related to possible intrusions or hydrothermal systems. The carbonatite body coincides with a steep magnetic gradient and a bench or terrace in the gravity data that may reflect relative lower-density intrusive rocks. Although carbonatite rocks are typically magnetic, the carbonatite rocks, associated intrusive suite, and host rocks in this area are essentially non-magnetic. Combined geophysical data indicate that the enriched REE deposit may be related to a regional extensive hydrothermal alteration event. 
