Understanding fluid transport in plutons: Isotopic compositions of hydrothermal-pipe features in the Tuolumne Intrusive Suite, CA

This study uses isotope geochemistry of lead and strontium as well as whole rock analysis of major and trace elements from 15 intrusive rock samples from the Tuolumne Intrusive Suite in eastern California, as well as multiple fluid feature samples:  nine hydrothermal pipes, two K-feldspar rafts, two ladder structures, and an additional six wall rock samples surrounding the suite. These samples were used to understand fluid transport in the Tuolumne post-emplacement as a proxy for hydrothermal alteration responsible for critical mineral and economic ore deposits. Whole-rock geochemistry showed that the hydrothermal pipes share a bulk-rock composition, particularly in rare-earth elements, with the host Tuolumne Intrusive Suite. The isotopic data revealed that the fluids creating the hydrothermal pipes in the Tuolumne Intrusive Suite in eastern California are not entirely derived from younger crystallizing magmas. The fluids are a potential combination of multiple origins and pulses throughout the suite, surrounding rock units, and other Sierran bodies.