DATING THE TRIANGLE OF DEATH: THE AGE AND RELATIONSHIPS OF ZIEGLER RESERVOIR, NATURAL TRAP CAVE, AND HOT SPRINGS MAMMOTH SITES

Paleoclimatic reconstructions at paleontological sites are of critical importance because they can provide a unique opportunity to set absolute dates to paleoenvironmental conditions during oxygen isotope stages 2 through 6 and beyond. To establish the ages of various sedimentary units at the site, researchers date the fossils, stratigraphy, and environmental markers (directly or indirectly) or use independent chronometric techniques such as radiocarbon (14C), surface exposure dating (in situ cosmogenic 10Be and 26Al), uranium series disequilibrium (U-series), and optically stimulated luminescence (OSL) dating. What should paleontological site researchers know about the OSL dating method before determining whether the site they have found would be suitable for the technique? What would be important to have at the site and what could be unimportant or missing and still guarantee an effective outcome? What else can OSL provide besides absolute dates?

Using three case histories of sites within the Rocky Mountain region (Ziegler Reservoir, Colorado 2013-2015; Hot Springs, South Dakota 2016-2018; and Natural Trap Cave, Wyoming 2015-2018), the appropriate steps and procedures will be explained and a template will be given for the successful dating program. Luminescence guides from Nelson et al 2015 and Gray et al 2015 will highlight sampling protocols while a review of the surprises in the ages obtained at each site will allow the audience to evaluate the bevy of luminescence techniques, equipment, and their utility for future projects. As the GSA community moves into the Anthropocene, OSL dating continues to be a versatile and useful tool for paleontological research.