Is the Isabella anomaly a fossil slab or the foundered lithospheric root of the Sierra Nevada batholith?

Charles R. Hoots1, Brandon Schmandt2, Robert W Clayton3, Steven M Hansen1 and Sara L Dougherty3, (1)University of New Mexico Main Campus, Albuquerque, NM, United States, (2)University of New Mexico, Earth and Planetary Sciences, Albuquerque, United States, (3)California Institute of Technology, Pasadena, CA, United States