Hanlin Zhang’21 Analyzes Hydrothermal Alteration of the Clay Cap in the Creede Mining District
The Creede mining district, located in Creede, Colorado, hosts epithermal Ag-Pb-Zn deposits along the Bachelor Caldera Fault System. Clay cap formation in the fault system is one of the stages of mineral deposition in Creede Mining District and altered volcanic tuffs with fluids from a number of sources. Prior research has been conducted in the southern side clay cap. Mineralogical, hydrothermal, stable isotopes and other general data indicate that the hydrothermal fluid altered rhyolite into smectite/illite, but other clay minerals occur locally.
My study aims to characterize the mineralogy, including clay mineralogy, and geochemistry of the clay cap to better understand the fluids involved in the hydrothermal system, and how the clay cap relates to other stages of mineralization and alteration, including early widespread K metasomatism in the district. The two main methods applied in this study are handheld X-ray fluorescence (pXRF) for whole rock geochemistry and X-ray diffraction (XRD) for clay mineralogy. Understanding hydrothermal conditions and alterations in clay cap formation can facilitate identification of hydrothermal characterized mineral ores for academic and economic purposes.