Progress in the search for early sites in the lower Salmon River canyon, Idaho : a case study in geoarchaeological prospection

Graduation date: 2015The search for and discovery of early archaeological sites is an inherently geoarchaeological problem. Archaeological sites of late Pleistocene-age are known to be located in the Intermountain West, however, the record of these early sites remains limited to only a few examples. In the lower Salmon River canyon (LSRC), the Cooper’s Ferry site has been shown to be of late Pleistocene age, however this early archaeological record remains limited to this site. In order to accelerate the process of discovery of these early sites in the LSRC, the present study mapped landforms, and investigated several natural exposures of sediments and soils in the Horseshoe Bend area of the Salmon River, Idaho. AMS radiocarbon ages were obtained on bulk soil organic matter from the truncated B horizons and A horizons of several buried soils. Soil morphology, radiocarbon ages, and sedimentary sequences suggest that a stable paleolandscape, signaled by soil formation across several landforms, was buried sometime after 12,700 yr BP in the study area, and has the potential of holding late Pleistocene to early Holocene-age archaeological sites