Sulfur Isotopes in Plutonic Rocks of the Great Basin as Indicators of Crustal Architecture

AbstractReconstructions of geologic provinces in the crust are an important component of understanding ancient plate tectonic processes and crustal evolution. Isotopic data from plutonic rocks, primarily Sr, Nd, Pb, and O, have been commonly utilized to delineate ancient geological provinces. Sulfur isotopes have not previously been utilized for province reconstruction, perhaps because of the difficulty in analysis and interpretation. We present here the results of the first large-scale effort at utilizing sulfur isotopes as an indicator of crustal architecture and demonstrate that sulfur is complementary to other isotopic measurements. We also show that, because of mass balance considerations, sulfur can be potentially a far more sensitive indicator of magma-crust interaction processes during magma migration through the crust than are other isotope systems. We anticipate that addition of sulfur isotope measurements to other studies of crustal evolution will provide significant insights into plate tectoni...