TY - JOUR
T1 - Absolute timing of sulfide and gold mineralization: A comparison of Re-Os molybdenite and Ar-Ar mica methods from the Tintina Gold Belt, Alaska
AU - Selby, D.
AU - Creaser, R.A.
AU - Hart, Craig
AU - Rombach, C.S.
AU - Thompson, J.F.H.
AU - Smith, M.T.
AU - Bakke, A.A.
AU - Goldfarb, R.J.
PY - 2002
Y1 - 2002
N2 - New Re-Os molybdenite dates from two lode gold deposits of the Tintina Gold Belt, Alaska, provide direct timing constraints for sulfide and gold mineralization. At Fort Knox, the Re-Os molybdenite date is identical to the U-Pb zircon age for the host intrusion, supporting an intrusive-related origin for the deposit. However, Ar-40/Ar-39 dates from hydrothermal and igneous mica are considerably younger. At the Pogo deposit, Re-Os molybdenite dates are also much older than Ar-40/Ar-39 dates from hydrothermal mica, but dissimilar to the age of local granites. These age relationships indicate that the Re-Os molybdenite method records the timing of sulfide and gold mineralization, whereas much younger Ar-40/Ar-39 dates are affected by post-ore thermal events, slow cooling, and/or systemic analytical effects. The results of this study complement a growing body of evidence to indicate that the Re-Os chronometer in molybdenite can be an accurate and robust tool for establishing timing relations in ore systems.
AB - New Re-Os molybdenite dates from two lode gold deposits of the Tintina Gold Belt, Alaska, provide direct timing constraints for sulfide and gold mineralization. At Fort Knox, the Re-Os molybdenite date is identical to the U-Pb zircon age for the host intrusion, supporting an intrusive-related origin for the deposit. However, Ar-40/Ar-39 dates from hydrothermal and igneous mica are considerably younger. At the Pogo deposit, Re-Os molybdenite dates are also much older than Ar-40/Ar-39 dates from hydrothermal mica, but dissimilar to the age of local granites. These age relationships indicate that the Re-Os molybdenite method records the timing of sulfide and gold mineralization, whereas much younger Ar-40/Ar-39 dates are affected by post-ore thermal events, slow cooling, and/or systemic analytical effects. The results of this study complement a growing body of evidence to indicate that the Re-Os chronometer in molybdenite can be an accurate and robust tool for establishing timing relations in ore systems.
U2 - 10.1130/0091-7613(2002)030<0791:ATOSAG>2.0.CO;2
DO - 10.1130/0091-7613(2002)030<0791:ATOSAG>2.0.CO;2
M3 - Article
VL - 30
SP - 791
EP - 794
JO - Geology
JF - Geology
SN - 0091-7613
ER -