J
James L. Crowley
Researcher at Boise State University
Publications - 171
Citations - 11788
James L. Crowley is an academic researcher from Boise State University. The author has contributed to research in topics: Zircon & Geochronology. The author has an hindex of 41, co-authored 141 publications receiving 9584 citations. Previous affiliations of James L. Crowley include Massachusetts Institute of Technology & University of Calgary.
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Journal ArticleDOI
Plesovice zircon : A new natural reference material for U-Pb and Hf isotopic microanalysis
Jirri Slama,Jirri Slama,Jirri Slama,Jan Košler,Daniel J. Condon,James L. Crowley,Axel Gerdes,John M. Hanchar,Matthew S.A. Horstwood,George A. Morris,Lutz Nasdala,Nicholas Norberg,Urs Schaltegger,Blair Schoene,Michael Tubrett,Martin J. Whitehouse +15 more
TL;DR: The Plesovice zircon as discussed by the authors has a concordant U-Pb age with a weighted mean Pb-206/U-238 date of 337.13 +/- 0.37 Ma (ID-TIMS, 95% confidence limits, including tracer calibration uncertainty).
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Calibrating the End-Permian Mass Extinction
Shu-zhong Shen,James L. Crowley,James L. Crowley,Yue Wang,Samuel A. Bowring,Douglas H. Erwin,Douglas H. Erwin,Peter M. Sadler,Changqun Cao,Daniel H. Rothman,Charles M. Henderson,Jahandar Ramezani,Hua Zhang,Yanan Shen,Xiangdong Wang,Wei Wang,Lin Mu,Wen-zhong Li,Yue-gang Tang,Xiao-Lei Liu,Lujun Liu,Yong Zeng,Yao-fa Jiang,Yugan Jin +23 more
TL;DR: High-precision geochronologic dating constrains probable causes of Earth's largest mass extinction and reveals that the extinction peak occurred just before 252.28 ± 0.08 million years ago, after a decline of 2 per mil (‰) in δ13C over 90,000 years, and coincided with a δ 13C excursion that is estimated to have lasted ≤20,000 Years.
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U-Pb zircon date from the Neoproterozoic Ghaub Formation, Namibia: Constraints on Marinoan glaciation
TL;DR: In this paper, U-Pb zircon geochronology of an ash layer constrains the deposition of the glaciomarine sediments to 635.5 ± 1.2 Ma, providing an age for what has been described as a "Marinoan-type" glaciation.
Journal ArticleDOI
Calibrating the Cryogenian.
Francis A. Macdonald,Mark D. Schmitz,James L. Crowley,Charles F. Roots,David S. Jones,Adam C. Maloof,Justin V. Strauss,Phoebe Cohen,David T. Johnston,Daniel P. Schrag +9 more
TL;DR: Four high-precision U-Pb ages for Neoproterozoic rocks in northwestern Canada are presented that constrain large perturbations in the carbon cycle, a major diversification and depletion in the microfossil record, and the onset of the Sturtian glaciation.
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Reassessing the uranium decay constants for geochronology using ID-TIMS U–Pb data
TL;DR: In this paper, the U-Pb systematics of zircon and xenotime on the single-to sub-grain scale by high-precision ID-TIMS geochronology on 11 rock samples ranging from 0.1 to 3.3 Ga.