Geochronology of late Pleistocene to Holocene speleothemsfrom central Texas: Implications for regional paleoclimate

Abstract

Research Article| December 01, 2001 Geochronology of late Pleistocene to Holocene speleothemsfrom central Texas: Implications for regional paleoclimate MaryLynn Musgrove; MaryLynn Musgrove 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Jay L. Banner; Jay L. Banner 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Larry E. Mack; Larry E. Mack 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Deanna M. Combs; Deanna M. Combs 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Eric W. James; Eric W. James 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Search for other works by this author on: GSW Google Scholar Hai Cheng; Hai Cheng 2Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA Search for other works by this author on: GSW Google Scholar R. Lawrence Edwards R. Lawrence Edwards 2Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA Search for other works by this author on: GSW Google Scholar Author and Article Information MaryLynn Musgrove 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Jay L. Banner 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Larry E. Mack 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Deanna M. Combs 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Eric W. James 1Department of Geological Sciences, University of Texas, Austin, Texas 78712, USA Hai Cheng 2Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA R. Lawrence Edwards 2Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA Publisher: Geological Society of America Received: 26 Jun 2000 Revision Received: 23 Apr 2001 Accepted: 09 May 2001 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2001) 113 (12): 1532–1543. https://doi.org/10.1130/0016-7606(2001)113<1532:GOLPTH>2.0.CO;2 Article history Received: 26 Jun 2000 Revision Received: 23 Apr 2001 Accepted: 09 May 2001 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation MaryLynn Musgrove, Jay L. Banner, Larry E. Mack, Deanna M. Combs, Eric W. James, Hai Cheng, R. Lawrence Edwards; Geochronology of late Pleistocene to Holocene speleothemsfrom central Texas: Implications for regional paleoclimate. GSA Bulletin 2001;; 113 (12): 1532–1543. doi: https://doi.org/10.1130/0016-7606(2001)113<1532:GOLPTH>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A detailed chronology for four stalagmites from three central Texas caves separated by as much as 130 km provides a 71 000-yr record of temporal changes in hydrology and climate. Mass spectrometric 238U-230Th and 235U-231Pa analyses have yielded 53 ages. The accuracy of the ages and the closed- system behavior of the speleothems are indicated by interlaboratory comparisons, concordance of 230Th and 231Pa ages, and the result that all ages are in correct stratigraphic order. Over the past 71 000 yr, the stalagmites have similar growth histories with alternating periods of relatively rapid and slow growth. The growth rates vary over more than two orders of magnitude, and there were three periods of rapid growth: 71–60 ka, 39–33 ka, and 24–12 ka. These growth-rate shifts correspond in part with global glacial-interglacial climatic shifts.Paleontological evidence indicates that around the Last Glacial Maximum (20 ka), climate in central Texas was cooler and wetter than at present. This wetter interval corresponds with the most recent period of increased growth rates in the speleothems, which is consistent with conditions necessary for speleothem growth. The temporal shift in wetness has been proposed to result from a southward deflection of the jet steam due to the presence of a continental ice sheet in central North America. This mechanism also may have governed the two earlier intervals of fast growth in the speleothems (and inferred wetter climate). Ice volumes were lower and temperatures in central North America were higher during these two earlier glacial intervals than during the Last Glacial Maximum, however. The potential effects of temporal variations in precession of Earth's orbit on regional effective moisture may provide an additional mechanism for increased effective moisture coincident with the observed intervals of increased speleothem growth. The stalagmites all exhibit a large drop in growth rate between 15 and 12 ka, and they show very slow growth up to the present, consistent with drier climate during the Holocene. These results illustrate that speleothem growth rates can reflect the regional response of a hydrologic system to regional and global climate variability. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.