Abstract
A stalagmite record of the penultimate deglaciation from northwestern Arkansas
Abstracts with programs - Geological Society of America, Vol.38(4), p.27
Geological Society of America, North-Central Section, 40th annual meeting
04/2006
Abstract
We present stable isotopic data from CS-04-5, a 54 cm-high, cylindrical calcite stalagmite from Cosmic Cavern, northwest Arkansas, which grew during the penultimate deglaciation (Termination 2). The chronology for CS-04-5 is based on six U-Th mass spectrometry dates, all of which fall in correct stratigraphic order (140.6+ or -1.9, 138.5+ or -2.6, 137.4+ or -2.1, 136.0+ or -2.5, 134.2+ or -2.0, and 128.7+ or -2.4 ka). Petrographic examination finds five growth hiatuses, none of which were of sufficient duration to fall outside the uncertainties on the radiometric dates. The stalagmite has been analyzed for oxygen and carbon isotope ratios from 139-136 and 133-128 ka. delta (super 18) O values exhibit a range of approximately approximately 0.5ppm, with a mean value of -5.4 ppm (PDB). The mean delta (super 13) C value is -10.0ppm (PDB) from 139-136 ka and 133-132 ka at which time there was an interruption in calcite deposition. When growth resumed at approximately 130 ka, delta (super 13) C values were -7ppm. The 3ppm increase in delta (super 13) C values at 130 ka can be attributed to a decrease in forest density over Cosmic Cavern or a change in water-rock interaction associated with an interglacial climate.
Details
- Title: Subtitle
- A stalagmite record of the penultimate deglaciation from northwestern Arkansas
- Creators
- Lara Moellers - Cornell CollegeRhawn F DennistonScott J CarpenterJeffrey A DoraleVictor J PolyakYemane Asmerom
- Resource Type
- Abstract
- Publication Details
- Abstracts with programs - Geological Society of America, Vol.38(4), p.27
- Conference
- Geological Society of America, North-Central Section, 40th annual meeting
- Publisher
- Geological Society of America (GSA)
- ISSN
- 0016-7592
- Alternative title
- Geological Society of America, North-Central Section, 40th annual meeting
- Language
- English
- Date published
- 04/2006
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984240801202771
Metrics
7 Record Views