Direct radiometric dating of the Devonian-Mississippian time-scale boundary using the Re-Os black shale geochronometer

Selby, D; Creaser, R.A

Abstract

Many Phanerozoic time-scale boundaries are characterized by oceanic anoxia and mass extinction events with the deposition of black shale. The Re-Os isotope system in black shale can be used to provide depositional ages for these rocks, thus yielding direct radiometric ages for time-scale boundaries. We demonstrate that the Re-Os black shale geochronometer can yield precise ages useful for time-scale research through study of the Devonian-Mississippian boundary within the Exshaw Formation, Canada. The Re-Os date determined places the Devonian-Mississippian boundary at 361.3 ± 2.4 Ma (2σ including λ uncertainty, model 1, mean square of weighted deviates = 1.2), in accord with recent calibration interpolated from U-Pb zircon dates (360.7 ± 0.7 Ma) for the Hasselbachtal section, Germany.

Citation

Selby, D., & Creaser, R. (2005). Direct radiometric dating of the Devonian-Mississippian time-scale boundary using the Re-Os black shale geochronometer. Geology, 33(7), 545-548. https://doi.org/10.1130/g21324.1

• Journal Article Type: Article
• Publication Date: 2005-07
• Deposit Date: Mar 13, 2007
• Journal: Geology
• Print ISSN: 0091-7613
• Electronic ISSN: 1943-2682
• Publisher: Geological Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 33
• Issue: 7
• Pages: 545-548
• DOI: https://doi.org/10.1130/g21324.1
• Keywords: Re-Os, Black shale, Geochronology, Devonian-Mississippian boundary.