Late Pleistocene palaeoenvironments, archaeology, and indicators of a glacial refugium on northern Vancouver Island, Canada by Christopher Franklin George Hebda B.A., University of Victoria, 2014 A Thesis Submitted in Partial Fulfillment of the Requirements for the Degree of MASTER OF ARTS in the Department of Anthropology © Christopher Franklin George Hebda, 2019 University of Victoria All rights reserved. This thesis may not be reproduced in whole or in part, by photocopy or other means, without the permission of the author. We acknowledge with respect the Lekwungen peoples on whose territory the university stands and the Songhees, Esquimalt and W̱ SÁNEĆ peoples whose historical relationships with the land continue to this day. ii Supervisory Committee Late Pleistocene palaeoenvironments, archaeology, and indicators of a glacial refugium on northern Vancouver Island, Canada by Christopher Franklin George Hebda B.A., University of Victoria, 2014 Supervisory Committee Dr. Quentin Mackie, Department of Anthropology Co-Supervisor Dr. Duncan McLaren, Department of Anthropology Co-Supervisor iii Abstract Recent research has revealed human settlement on the Pacific coast of Canada extending back nearly 14,000 years, but much of the late Pleistocene record is unknown due to shifting sea levels, poor understanding of Cordilleran ice extent, and limited research on the biota of the coast during this time. This study, undertaken in Quatsino First Nation and ‘Namgis First Nation territories as part of the Northern Vancouver Island Archaeology and Palaeoecology Project, employs modern multi-proxy analysis of lake sediment cores from two sites on northern Vancouver Island to reconstruct palaeoenvironments during and immediately following the Fraser Glaciation in coastal British Columbia. Evidence from radiocarbon samples, pollen, ancient environmental DNA, plant macrofossils, and diatoms indicates that Topknot Lake on the outer coast of Vancouver Island has remained unglaciated through most of the local Last Glacial Maximum since ca. 18,000 cal BP. A non-arboreal herb-shrub tundra assemblage prevailed from ca. 17,500-16,000 cal BP with taxa including willows (Salix), grasses, sedges (Cyperaceae), heathers (Ericaceae), and sagewort (Artemisia). After ca. 16,000 and into the terminal Pleistocene, Topknot Lake was dominated by pine, alder (Alnus), ferns, and aquatic plant species. In the Nimpkish River Valley deep in the Vancouver Island Ranges, Little Woss Lake also demonstrates a record extending to the late Pleistocene (ca. 14,300 cal BP). The environment comprised dry and cool conifer woodland dominated first by fir (Abies) until ca. 14,000 cal BP, then by pine, alder, and ferns from ca. 14,000-12,000 cal BP. eDNA evidence from ca. 14,000 cal BP corroborates these plant taxa as well as indicating brown bear and Chinook salmon in and around the basin at that time. A mixed-conifer assemblage consisting of pine, western hemlock, and alder followed from ca. 12,000-11,100 cal BP into the early Holocene. Collectively, these indicators demonstrate an open environment on the outer coast of northern Vancouver Island since ca. 18,000-17,500 cal BP and well-established biotic communities across the region throughout the late Pleistocene. These results inform future archaeological research for early human habitation in coastal British Columbia and provide key evidence to support the viability of the coastal migration route for the first peopling of the Americas. iv Table of Contents Supervisory Committee .................................................................................................... ii Abstract ............................................................................................................................. iii Table of Contents ............................................................................................................. iv List of Figures ................................................................................................................... vi List of Tables ................................................................................................................... vii Acknowledgements ........................................................................................................ viii 1. Introduction ................................................................................................................... 1 1.1 Context and Research Questions ..................................................................................... 1 1.2 Chapter Organization ....................................................................................................... 5 2. Background ................................................................................................................... 7 2.1 Environmental Setting ...................................................................................................... 7 2.1.1 Physiographic Regions of Vancouver Island ............................................................. 7 2.1.2 Study Sites ................................................................................................................. 9 2.2 Glacial History and Relative Sea Level Change on the Northwest Coast .................. 15 2.2.1 Late Pleistocene Glaciation on the Northwest Coast ............................................... 15 2.2.2 Global Eustatic Sea Level Change ........................................................................... 29 2.2.3 Documenting Glacio-Isostatic Effects on Sea Level History .................................. 30 2.2.4 Relative Sea Level Change on the Northwest Coast ................................................ 33 2.3 Late Pleistocene Palaeoecology of the Northwest Coast .............................................. 41 2.4 Late Pleistocene/Early Holocene Archaeology of the Northwest Coast ..................... 55 3. Materials and Methods ............................................................................................... 61 3.1 Program of Research ....................................................................................................... 61 3.1.1 Established Methods ................................................................................................ 61 3.1.2 Program of Research ................................................................................................ 62 3.2 Methods ............................................................................................................................ 64 3.2.1 Fieldwork ................................................................................................................. 64 3.2.2 Subsampling ............................................................................................................. 68 3.2.3 Lab Work ................................................................................................................. 72 3.2.4 Data Analysis and Presentation ............................................................................... 81 4. Results and Discussion – ‘Article’ ............................................................................. 83 4.1 Introduction ..................................................................................................................... 83 4.2 Regional Setting ............................................................................................................... 85 v 4.3 Glacial History ................................................................................................................. 86 4.4 Palaeoecology ................................................................................................................... 89 4.5 Late Pleistocene Archaeology ......................................................................................... 91 4.6 Materials and Methods ................................................................................................... 93 4.6.1 Coring ...................................................................................................................... 95 4.6.2 Subsampling and Preparation .................................................................................. 96 4.6.3 Lab Work and Analysis ........................................................................................... 97 4.7 Results .............................................................................................................................. 99 4.7.1 Little Woss Lake ...................................................................................................... 99 4.7.2 Topknot Lake ......................................................................................................... 113 4.8 Discussion ....................................................................................................................... 133 4.8.1 Late Pleistocene Glacial History of Northern Vancouver Island ........................... 133 4.8.2 Late Pleistocene Palaeoecology of Northern Vancouver Island ............................ 139 4.8.3 Regional Stability and Glacial Refugia .................................................................. 149 4.8.4 Implications for the Coastal Migration Route and the Peopling of the Americas . 153 4.9 Conclusions .................................................................................................................... 160 5. Conclusions and Future Directions ........................................................................