Reporting and Interpretation of Geochronologic Data
Organized by the GSA Bulletin science editors.
As emphasized in the recent National Academy of Sciences Consensus Report The Earth in Time, geochronology has become central to addressing processes spanning many temporal and spatial scales. The conclusions of papers published in the Bulletin and other journals increasingly rely on radioisotopic dating of minerals, rocks, and organic materials. However, there are many radioisotopic and other dating methods in use, some are novel, data sets are commonly large and often contain dozens to thousands of isotopic measurements, and with ever increasing precision, the interpretation of large complex data sets is not always straightforward. Moreover, standardization of many methods has been greatly improved, but a plethora of standard values often requires re-calibration of published data sets.
For several widely used chronometers, the papers of this themed issue aim to: (1) present a brief overview, including the fundamental assumptions and sources of uncertainty, (2) discuss what materials are most suited for analysis and how these are collected in the field and prepared in the laboratory, (3) address the limits on the age range of applicability, (4) review the principal applications, (5) recommend minimum requirements for data and metadata reporting about samples and the isotopic information derived from them with an eye towards archiving the data in a format that will be accessible for the foreseeable future, and (6) provide examples of the challenges to interpreting data and determining geological ages from complex sets of dates. We intend that these papers will become a valuable resource for authors who generate, organize, and interpret geochronologic data for publication, as well as for editors, associate editors, and reviewers who must evaluate the integrity of geochronologic data sets and the conclusions based upon them.
Contributions are listed below in the order they were published.
Interpreting and reporting 40Ar/39Ar geochronologic data
Schaen et al.