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Interpreting and reporting (super 40) Ar/ (super 39) Ar geochronologic data

Allen J. Schaen, Brian R. Jicha, Kip V. Hodges, Pieter Vermeesch, Mark E. Stelten, Cameron M. Mercer, David Phillips, Tiffany A. Rivera, Fred Jourdan, Erin L. Matchan, Sidney R. Hemming, Leah E. Morgan, Simon P. Kelley, William S. Cassata, Matt T. Heizler, Paulo M. Vasconcelos, Jeff A. Benowitz, Anthony A. P. Koppers, Darren F. Mark, Elizabeth M. Niespolo, Courtney J. Sprain, Willis E. Hames, Klaudia F. Kuiper, Brent D. Turrin, Paul R. Renne, Jake Ross, Sebastien Nomade, Herve Guillou, Laura E. Webb, Barbara A. Cohen, Andrew T. Calvert, Nancy Joyce, Morgan Ganerod, Jan Wijbrans, Osamu Ishizuka, He Huaiyu, Adan Ramirez, Joerg A. Pfaender, Margarita Lopez-Martinez, Qiu Huaning and Brad S. Singer
Interpreting and reporting (super 40) Ar/ (super 39) Ar geochronologic data
Geological Society of America Bulletin (July 2020) Pre-Issue Publication


The 40Ar/39Ar dating method is among the most versatile of geochronometers, having the potential to date a broad variety of K-bearing materials spanning from the time of Earth's formation into the historical realm. Measurements using modern noble-gas mass spectrometers are now producing 40Ar/39Ar dates with analytical uncertainties of approximately 0.1%, thereby providing precise time constraints for a wide range of geologic and extraterrestrial processes. Analyses of increasingly smaller subsamples have revealed age dispersion in many materials, including some minerals used as neutron fluence monitors. Accordingly, interpretive strategies are evolving to address observed dispersion in dates from a single sample. Moreover, inferring a geologically meaningful "age" from a measured "date" or set of dates is dependent on the geological problem being addressed and the salient assumptions associated with each set of data. We highlight requirements for collateral information that will better constrain the interpretation of 40Ar/39Ar data sets, including those associated with single-crystal fusion analyses, incremental heating experiments, and in situ analyses of microsampled domains. To ensure the utility and viability of published results, we emphasize previous recommendations for reporting 40Ar/39Ar data and the related essential metadata, with the amendment that data conform to evolving standards of being findable, accessible, interoperable, and reusable (FAIR) by both humans and computers. Our examples provide guidance for the presentation and interpretation of 40Ar/39Ar dates to maximize their interdisciplinary usage, reproducibility, and longevity.

ISSN: 0016-7606
EISSN: 1943-2674
Serial Title: Geological Society of America Bulletin
Serial Volume: Pre-Issue Publication
Title: Interpreting and reporting (super 40) Ar/ (super 39) Ar geochronologic data
Affiliation: University of Wisconsin-Madison, Department of Geoscience, Madison, WI, United States
Published: 20200701
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 259
Accession Number: 2020-062980
Categories: General geochemistryGeochronology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 5 tables, sketch map
Secondary Affiliation: Arizona State University, USA, United StatesUniversity College London, GBR, United KingdomU. S. Geological Survey, USA, United StatesNASA Goddard Space Flight Center, USA, United StatesUniversity of Melbourne, AUS, AustraliaWestminster College, USA, United StatesCurtin University, AUS, AustraliaLamont-Doherty Earth Observatory, USA, United StatesUniversity of Edinburgh, GBR, United KingdomLawrence Livermore National Laboratory, USA, United StatesNew Mexico Institute of Mining and Technology, USA, United StatesUniversity of Queensland, AUS, AustraliaUniversity of Alaska-Fairbanks, USA, United StatesOregon State University, USA, United StatesScottish Universities Environmental Research Centre, GBR, United KingdomBerkeley Geochronology Center, USA, United StatesUniversity of Florida, USA, United StatesAuburn University, USA, United StatesVrije University Amsterdam, NLD, NetherlandsRutgers-State University of New Jersey, USA, United StatesUniversity of St. Andrews, GBR, United KingdomInstitut Pierre Simon Laplace, FRA, FranceUniversite Paris-Saclay, FRA, FranceUniversity of Vermont, USA, United StatesGeological Survey of Canada, CAN, CanadaGeological Survey of Norway, NOR, NorwayGeological Survey of Japan, JPN, JapanChinese Academy of Sciences, College of Earth Sciences, CHN, ChinaServicio National de Geologia y Mineria, CHL, ChileTechnische Universitaet Freiberg, DEU, GermanyCentro de Investigacion Cientifica y de Educacion Superior de Ensenada, Departamento de Geologia, MEX, MexicoChina University of Geosciences, CHN, China
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2020, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 202018
Program Name: USGSOPNon-USGS publications with USGS authors
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