[meteorite-list] Odessa Impact Crater and OSL Dating
From: Paul <bristolia_at_meteoritecentral.com>
Date: Wed, 28 Oct 2009 04:29:05 -0700 (PDT) Message-ID: <208635.16904.qm_at_web36207.mail.mud.yahoo.com> E.P. Grondine wrote: ?When I visited Odessa I was told that it was suspected to be the impact of a fragment related to the Barringer impactor. My suspicion is that the Barringer impact is seen in the spike of C14 in the INTCAL98 chart around 45,000 BCE. So what is OSL dating anyway, and how accurate is it?? The details of the dating of the Odessa crater is discussed in: Holliday, V. T., D. A. Kring, J. H. Mayer, and R. J. Goble, 2005, Age and effects of the Odessa meteorite impact, western Texas, USA. Geology. vol. 33, no. 12, pp. 945-947. Its abstract reads: ?Dating by optically stimulated luminescence indicates that it was produced immediately prior to ca. 63.5+/- 4.5 ka. Sediment filling the crater includes impact breccias produced at the time of impact; wind-dominated silts with minor amounts of pond sediments deposited ca. 63.5 ka, probably just after the impact...? The PDf file can be found at: http://www.argonaut.arizona.edu/articles/holliday_etal2005.pdf http://www.argonaut.arizona.edu/holliday.htm Optically stimulated luminescence (OSL) dating can be quite accurate as cross-dating between contemporaneous OSL and radiocarbon samples has demonstrated. As with any other dating methods a person has to be careful in only dating materials that can be reliably dated; in how they collect the samples; and how they transport the samples to the OSL lab. Single-grain OSL dating of sediments is the most reliable way of OSL dating sediments. Web pages about OSL dating are ?Luminescence Dating - Introduction and Overview of the the Technique? at: http://crustal.usgs.gov/laboratories/luminescence_dating/technique.html and "Optically Stimulated Luminescence (OSL)" at: http://www.uic.edu/labs/ldrl/about.html http://www.uic.edu/labs/ldrl/osl.html A few of many, many papers and articles on OSL dating are: 1. Murray, A. M., J. M. Olley, 2002, Precision and accuracy in the optically stimulated luminescence dating of sedimentary quartz. Geochronometria. vol. 21, pp 1-16. http://www.carbon14.pl/geo/pdf/Geo21.pdf. 2. Ballarini, M., 2006, Optical Dating of Quartz from Young Deposits From Single-Aliquot to Single-Grain. Delft University Press, Amsterdam, The Netherlands. http://repository.tudelft.nl/file/224774/190288 3. optically stimulated luminescence dating? an introduction http://geoinfo.nmt.edu/publications/periodicals/nmg/29/n4/1%20OSLintro.pdf Yours, Paul H. Received on Wed 28 Oct 2009 07:29:05 AM PDT |
StumbleUpon del.icio.us Yahoo MyWeb |