Description

Location: Western Folk Life Center

Contact: justin.b.milliard@gmail.com

The Elko GSN Chapter is excited to have Alexander Holmwood from UNR presenting his Masters Thesis research on Majuba Hill. ORLA Mining  is generously sponsoring the meeting.

LOCATION:  Western Folk Life Center, 501 Railroad St., Elko, NV

DATE:  Thursday, January 19, 2023

TIME:  Food and drinks @ 6 pm and talk to begin at 7 pm.

SPONSOR:  ORLA MINING

Presenter:  Alexander Holmwood, University of Nevada, Reno

Title:  “Temporal Evolution of the Majuba Hill Cu-(Mo)-(Sn) Deposit, Pershing County, Nevada”

Abstract: 

The Majuba Hill intrusive complex of Pershing County, Nevada, is an atypical example of a polymetallic Cu-(Mo)-(Sn) mineral deposit hosted in hypabyssally-emplaced rhyolites. The objective of this graduate research project is to evaluate the possibility that Majuba Hill is a rhyolite-hosted Sn deposit that has been overprinted by a porphyry Cu-(Mo) system. Completing this project will rely on determining the paragenetic sequence of alteration and mineralization events, performing whole-rock geochemistry, and performing geochronology of representative intrusives and mineralization events. Observations collected by transmitted light microscopy indicate that at least three hydrothermal stages are responsible for the alteration and mineralization assemblages present at Majuba Hill: 1) an early tourmaline-cassiterite-quartz±fluorite stage followed by tourmaline-quartz-fluorite crystallization, 2) a protracted hypogene pyrrhotite, chalcopyrite, pyrite-marcasite, and sphalerite stage, and 3) a supergene digenite, covellite, and hematite stage accompanied by various Cu-bearing and U- bearing secondary minerals. Whole-rock geochemical data collected from rhyolitic host rocks indicate they are strongly fractionated and were hydrothermally altered by alkali leaching and silicification. These data support the hypothesis that Sn is derived from the intrusive rhyolite complex and that hypogene Cu and Mo are sourced from a less evolved intrusion at depth.

Details

01/19/2023 18:00:0001/19/2023 21:00:00America/Los_AngelesGSN Elko Chapter Meeting – January 19, 2023The Elko GSN Chapter is excited to have Alexander Holmwood from UNR presenting his Masters Thesis research on Majuba Hill. ORLA Mining  is generously sponsoring the meeting. LOCATION:  Western Folk Life Center, 501 Railroad St., Elko, NV DATE:  Thursday, January 19, 2023 TIME:  Food and drinks @ 6 pm and talk to begin at 7 pm.

SPONSOR:  ORLA MINING

Presenter:  Alexander Holmwood, University of Nevada, Reno Title:  “Temporal Evolution of the Majuba Hill Cu-(Mo)-(Sn) Deposit, Pershing County, Nevada” Abstract:  The Majuba Hill intrusive complex of Pershing County, Nevada, is an atypical example of a polymetallic Cu-(Mo)-(Sn) mineral deposit hosted in hypabyssally-emplaced rhyolites. The objective of this graduate research project is to evaluate the possibility that Majuba Hill is a rhyolite-hosted Sn deposit that has been overprinted by a porphyry Cu-(Mo) system. Completing this project will rely on determining the paragenetic sequence of alteration and mineralization events, performing whole-rock geochemistry, and performing geochronology of representative intrusives and mineralization events. Observations collected by transmitted light microscopy indicate that at least three hydrothermal stages are responsible for the alteration and mineralization assemblages present at Majuba Hill: 1) an early tourmaline-cassiterite-quartz±fluorite stage followed by tourmaline-quartz-fluorite crystallization, 2) a protracted hypogene pyrrhotite, chalcopyrite, pyrite-marcasite, and sphalerite stage, and 3) a supergene digenite, covellite, and hematite stage accompanied by various Cu-bearing and U- bearing secondary minerals. Whole-rock geochemical data collected from rhyolitic host rocks indicate they are strongly fractionated and were hydrothermally altered by alkali leaching and silicification. These data support the hypothesis that Sn is derived from the intrusive rhyolite complex and that hypogene Cu and Mo are sourced from a less evolved intrusion at depth.
Reno, NV
Event StartsEvent Ends
01/19/202301/19/2023
All Day Event
6:00pm9:00pm