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Absolute timing of sulfide and gold mineralization: A comparison of Re-Os molybdenite and Ar-Ar mica methods from the Tintina Gold Belt, Alaska

Geology

By:
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DOI: 10.1130/0091-7613(2002)030<0791:ATOSAG>2.0.CO;2

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Abstract

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, 40Ar/39Ar dates from hydrothermal and igneous mica are considerably younger. At the Pogo deposit, Re-Os molybdenite dates are also much older than 40Ar/39Ar 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 40Ar/39Ar 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.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Absolute timing of sulfide and gold mineralization: A comparison of Re-Os molybdenite and Ar-Ar mica methods from the Tintina Gold Belt, Alaska
Series title:
Geology
DOI:
10.1130/0091-7613(2002)030<0791:ATOSAG>2.0.CO;2
Volume
30
Issue:
9
Year Published:
2002
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geology
First page:
791
Last page:
794
Number of Pages:
4