57
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: not found
      • Article: not found

      Synchronizing Rock Clocks of Earth History

      , , , , ,

      Science

      American Association for the Advancement of Science (AAAS)

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Calibration of the geological time scale is achieved by independent radioisotopic and astronomical dating, but these techniques yield discrepancies of approximately 1.0% or more, limiting our ability to reconstruct Earth history. To overcome this fundamental setback, we compared astronomical and 40Ar/39Ar ages of tephras in marine deposits in Morocco to calibrate the age of Fish Canyon sanidine, the most widely used standard in 40Ar/39Ar geochronology. This calibration results in a more precise older age of 28.201 +/- 0.046 million years ago (Ma) and reduces the 40Ar/39Ar method's absolute uncertainty from approximately 2.5 to 0.25%. In addition, this calibration provides tight constraints for the astronomical tuning of pre-Neogene successions, resulting in a mutually consistent age of approximately 65.95 Ma for the Cretaceous/Tertiary boundary.

          Related collections

          Most cited references 35

          • Record: found
          • Abstract: not found
          • Article: not found

          Subcommission on geochronology: Convention on the use of decay constants in geo- and cosmochronology

            Bookmark
            • Record: found
            • Abstract: not found
            • Article: not found

            A new geomagnetic polarity time scale for the Late Cretaceous and Cenozoic

              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              Intercalibration of standards, absolute ages and uncertainties in 40Ar/39Ar dating

                Bookmark

                Author and article information

                Journal
                Science
                Science
                American Association for the Advancement of Science (AAAS)
                0036-8075
                1095-9203
                April 25 2008
                April 25 2008
                : 320
                : 5875
                : 500-504
                Article
                10.1126/science.1154339
                18436783
                © 2008

                Comments

                Comment on this article