BLUEFISH CAVES REVISITED: A GEOARCHAEOLOGICAL AND PALEOENVIRONMENTAL ASSESSMENT OF A POTENTIAL PRE-CLOVIS SITE IN THE YUKON TERRITORY OF NORTHWESTERN CANADA (Invited Presentation)

Bluefish Caves, a cluster of four small rockshelters in the Yukon Territory of NW Canada, was excavated during the 1970s and 80s under the direction of Jacques Cinq-Mars. Caves I, II, and III yielded faunal remains dating to ca. 30-10 ka contained in loess, plus artifacts. Also, AMS ¹⁴C ages determined on cut-marked bones identified during a recent taphonomic analysis of the faunal assemblage suggests that humans occupied the site as early as 24 ka. Hence, Bluefish Caves may be the oldest recorded archaeological site in North America, and the findings support the “Beringian standstill hypothesis,” which proposes that a genetically isolated human population persisted in Beringia during the Last Glacial Maximum (LGM) and dispersed from there to North and South America during the post-LGM period. However, the stratigraphic context of the artifacts and evidence of anthropogenic bone modification have been challenged.

Here, we report results of our recent investigations at caves III and IV. In 2019, limited archaeological testing was conducted at Cave III to gain a better understanding of site formation processes. Also, soil/sediment samples were collected for ancient DNA (sedaDNA) analysis to determine the feasibility of isolating and sequencing ancient genetic material of transitional late Pleistocene/early Holocene flora and fauna from subarctic loess. Following initial processing of sedaDNA samples, sequences suggest recovery of sufficient nucleic acids for identification of multiple taxa in those samples, thereby providing a more robust picture of LGM and post-LGM paleoenvironments in the region. Also, we relocated Cave IV, which was not excavated by Jacques Cinq-Mars. The entrance and interior of Cave IV are almost filled with sediments. In July 2022, we tested the area in front of the cave, exposing a ~1-m-thick deposit of loess containing remains of horse, caribou, and other late-Pleistocene fauna. Many of the bones will be ¹⁴C dated, and sediment removed from the test units will be fine-screened for micro-debitage. Also, soil/sediment samples were collected for sedaDNA analysis, and ongoing micromorphological and sedimentological analyses of the loess will help us gain a better understanding of site formation processes and the spatial integrity of any cultural deposits found in Cave IV.