GEOARCHAEOLOGY IN BEARS EARS NATIONAL MONUMENT - HOLOCENE STREAM DYNAMICS IN AN ARID ENVIRONMENT

Bears Ears National Monument (BENM), established by President Obama in late 2016, includes a sweeping expanse of mesas, buttes, and canyons in southeastern Utah, including the spectacular "Comb Ridge" monocline. In addition to these geologic resources, at the heart of BENM is its extraordinary concentration of well-preserved archaeological sites. Despite the incredible concentration and preservation of archaeological sites in the region, very little work has focused on providing a geo-archeological context for these sites.

Here we present the results of preliminary investigations into the Holocene histories of streams in BENM, which would certainly been of utmost importance to the sustainability of cultures in this harsh landscape. We focus on Butler Wash, which hosts some of the more spectacular sites in the monument and was likely utilized for agriculture starting in the mid-late Holocene. Butler Wash appears to have undergone a number of arroyo "cut-and-fill" cycles in the late Holocene, with the scale of vertical channel movement approaching 15 m. We present a suite of new radiocarbon ages in an attempt to clarify the timing of these cycles, and consider how they could have affected contemporary cultures. Further, we evaluate the potential for preservation of Paleoindian-age sites in the Monument.