Abstract
The systematic distribution of vein and alteration mineral assemblages in porphyry Cu deposits largely arises from changes in the temperature and pressure of fluids that traversed fractures throughout the hydrothermal system. Magmatic and hydrothermal minerals record the complex history of the fluctuating temperature and pressure regime as hydrothermal fluids transfer heat from their magmatic source to cold wall rock in response to lithostatic-to-hydrostatic pressure variations. We examine the thermal profile of the porphyry Cu-Mo deposit in Butte, Montana, by determining formation temperatures for magmatic and hydrothermal samples representing different time frames and depths within the deposit, in context with sample pressure estimates. We use three independent mineral thermobarometers: Ti in quartz, Zr in rutile, and X Mg -Ti in biotite, from which we estimate that final dike injection temperature, and hence the initial magmatic-hydrothermal fluid temperature, was ~700°C while the ambient host-rock temperature was ~450° to 500°C. We find a magmatic-hydrothermal continuum represented in hydrothermal veins, ranging from ~710° to
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
