Absolute timing of sulfide and gold mineralization: A comparison of Re-Os molybdenite and Ar-Ar mica methods from the Tintina Gold Belt, Alaska
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.
Citation Information
Publication Year | 2002 |
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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 |
DOI | 10.1130/0091-7613(2002)030<0791:ATOSAG>2.0.CO;2 |
Authors | D. Selby, R.A. Creaser, C.J.R. Hart, C. S. Rombach, J. F. H. Thompson, Moira T. Smith, A.A. Bakke, R.J. Goldfarb |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Geology |
Index ID | 70024269 |
Record Source | USGS Publications Warehouse |