The origin of brucite in hydrothermally altered limestone near Devil Peak, Nevada

摘要: The Origin of Brucite in Hydrothermally Altered Limestone Near .Devil Peak, Nevada by Rhonda Knupp Dr. Rodney Metcalf; Examination Committee Chair Associate Professor Geology University ofNevada, Las Vegas Open-space brucite was identified veins crosscutting hydrothermally altered limestone near the Devil Peak rhyolite plug southern Nevada. occurs with serpentine, calcite, chalcedony, hydromagnesite, dolomite, and clinochlore. usually forms as a replacement mineral, but textural evidence indicates that at precipitated open space. presence chalcedony temperature hydrothermal fluid was< 180°C during after mineral deposition. Thermodynamic modeling shows this is too low for to fonn, thus alteration may be factor unusual occurrence brucite. Infiltration isotopically depleted wall rocks initially composed mixture metamorphic meteoric water, Xc02 = 0.15-0.16. Later, an influx magmatic or water