Paper No. 6
Presentation Time: 9:40 AM
PALEONTOLOGY OF PORT ELIZA CAVE, VANCOUVER ISLAND, CANADA: A RECORD FROM BEFORE AND AFTER THE LAST GLACIAL MAXIMUM AND IMPLICATIONS FOR EARLY HUMAN MIGRATIONS
The Port Eliza Cave strata preserve a record from before the Last Glacial Maximum, through the LGM, to early postglacial times. Pre- and post-LGM fossiliferous cave-floor deposits are separated by laminated fine sediments deposited when the cave was blocked by ice. Over 4000 bones were recovered, as well as shells, mostly from the pre-LGM faunule. The diverse pre-LGM faunule (~18,000 – 16,000 14C yr BP; 21,750 – 19,000 cal BP) includes bivalves, barnacles, fish (9 species), toads, birds (>7 species), and mammals (7 species) and may in part have been predator-accumulated. Abundant toad remains suggest use of the cave as a hibernaculum. Two of three vole species do not occur on this large island today, though they are present on the nearby mainland. Postglacial material (from ~12,400 14C yr BP or 15,000 cal BP onward) includes only two mammal species, reflecting more restricted access to the cave. Mountain goat (Oreamnos americanus), occuring in both faunules, was one of the last mammal species to leave and among the first to reoccupy Vancouver Island after glacial retreat, though it is not on the island today. Mountain goats may have survived the LGM in small refugia along the Cordilleran ice margin, either on the platform west of Vancouver Island or on exposed banks to the north, if not on the Olympic Peninsula to the south. The overall fauna suggests a cool, steppe-like environment capable of supporting migrating coastal human populations before 19,000 cal BP and after 15,000 cal BP. These people need not have had a specialized adaptation to littoral resources, but could harvested a wide range of marine, littoral, and terrestrial species. Given the presence of refugia and non-synchroneity of glacial advance/retreat between Alaska and Puget Sound, human groups with watercraft could potentially have explored southward along the Alaska and British Columbia coastlines even through much of the Last Glacial Maximum.