New Mexico Geological Society Annual Spring Meeting — Abstracts

There are well-established reoccurring climate change events during the last glacial period in the Northern Hemisphere as seen in Greenland ice core records. These events preserved in the ice cores are defined as Greenland stadials (GS) and interstadials (GI), and led to or were associated with reorganization of atmosphere temperature-pressure and ocean circulation surface temperature gradients in the Northern Hemisphere. However, to what extent they represent changes in effective moisture and temperature at regional scales remains unknown. The aim of this project is to provide constraints on what extent the changes seen in the Greenland ice core records represent changes in moisture and temperature in southwestern North America (SWNA). To determine this, we will use a speleothem from Carlsbad Cavern in the Guadalupe Mountains that was collected from a site that is thought to be sensitive to changes in temperature and moisture because of the short connection to the surface. Precise ages on the speleothem will be obtained using uranium (U)-series radiometric dating to establish a high-resolution chronology for a period between 50 and 30 ka. Stable isotopic values of d¹⁸O and d¹³C have been obtained for stalagmite CaCa-BC5, which was collected in the Main Corridor in Bat Cave Passage. The stable isotope time-series will be used to make interpretations regarding regional temperature, effective moisture, and precipitation variability. Some preliminary strontium (Sr)-isotope paleothermometry work will be included in this study to help in determining regional temperatures. Furthermore, comparisons with other speleothem records and continental proxies will provide additional framework for determining the SWNA regional climate response.