Andrew Martindale

Spatiotemporal distribution of Holocene populations in North America

Significance We provide the first maps to our knowledge of spatiotemporal paleodemographic growth following human migration into the Americas for the past 13,000 y, using a statistical approach that simultaneously addresses sampling and taphonomic biases. The Canadian Archaeological Radiocarbon Database is sufficiently complete in many areas, demonstrating high correspondence between continental-scale 14C-inferred population estimates and generally accepted archaeological history. Increases in population density seem robust for eastern and western North America, as well as central Alaska and the region surrounding Cahokia. These results are the first step toward being able to understand continental-scale human impacts on the North American ecosystem during the Holocene as well as demographic growth and migrations in relation to environmental changes. As the Cordilleran and Laurentide Ice Sheets retreated, North America was colonized by human populations; however, the spatial patterns of subsequent population growth are unclear. Temporal frequency distributions of aggregated radiocarbon (14C) dates are used as a proxy of population size and can be used to track this expansion. The Canadian Archaeological Radiocarbon Database contains more than 35,000 14C dates and is used in this study to map the spatiotemporal demographic changes of Holocene populations in North America at a continental scale for the past 13,000 y. We use the kernel method, which converts the spatial distribution of 14C dates into estimates of population density at 500-y intervals. The resulting maps reveal temporally distinct, dynamic patterns associated with paleodemographic trends that correspond well to genetic, archaeological, and ethnohistoric evidence of human occupation. These results have implications for hypothesizing and testing migration routes into and across North America as well as the relative influence of North American populations on the evolution of the North American ecosystem.

Seasonality and Intensity of Shellfish Harvesting on the North Coast of British Columbia

ABSTRACT Biogeochemical and growth increment analyses show contrasting seasonal patterns of butter clam collection and rates of harvest intensity between archaeological shell midden sites from the Dundas Islands archipelago and the mainland coast in Prince Rupert Harbour, northern British Columbia. Growth increment analysis shows more intensive clam harvest in the Dundas Islands in comparison to the residential sites in Prince Rupert Harbour. Stable oxygen isotope analysis shows multi-seasonal collection of clams in the Dundas Islands and a more seasonally specific emphasis in Prince Rupert Harbour. Comparison of these results to those of similar studies in the Namu region on the central coast of British Columbia provides a basis for broader regional understanding of variation in shellfish harvesting intensity and seasonality on the Pacific Northwest Coast.

A Marine Reservoir Effect ∆R Value for Kitandach, in Prince Rupert Harbour, British Columbia, Canada

Prince Rupert Harbour (PRH), on the north Pacific Coast of British Columbia, contains at least 157 shell middens, of which 66 are known villages, in an area of approximately 180 km 2 . These sites span the last 9500 yr and in some cases are immense, exceeding 20,000 m 2 surface area and several meters in depth. Recent archaeological research in PRH has become increasingly reliant on radiocarbon dates from marine shell for developing chronologies. However, this is problematic as the local marine reservoir effect (MRE) remains poorly understood in the region. To account for the MRE and to better date the Harbour’s sites, we propose a ΔR of 273±38 for the PRH area, based on our work at the site of Kitandach (GbTo-34), a massive shell midden-village centrally located within the Harbour. We followed the multiple paired sample approach for samples from specific contexts and ensured contemporaneity within the groups of marine and terrestrial materials by statistically assessing for outliers using the χ 2 test. Taking together, the results for this and previous studies, it appears the MRE was fairly constant over the past 5000 yr.

Radiocarbon test for demographic events in written and oral history

Significance Indigenous oral traditions remain a very controversial source of historical knowledge in Western scientific, humanistic, and legal traditions. Likewise, demographic models using radiocarbon-based simulation methods are controversial. We rigorously test the historicity of indigenous Tsimshian oral records (adawx) using an extended simulation-based method. Our methodology is able to detect short-duration (1–2 centuries) demographic events. First, we successfully test the methodology against a simulated radiocarbon dataset for the catastrophic European Black Death/bubonic plague (Yersinia pestis). Second, we test the Tsimshian adawx accounts of an occupational hiatus in their territorial heartland ca. 1,500–1,000 years ago. We are unable to disconfirm the oral accounts. This represents the first formal test of indigenous oral traditions using modern radiocarbon modeling techniques. We extend an established simulation-based method to test for significant short-duration (1–2 centuries) demographic events known from one documented historical and one oral historical context. Case study 1 extrapolates population data from the Western historical tradition using historically derived demographic data from the catastrophic European Black Death/bubonic plague (Yersinia pestis). We find a corresponding statistically significant drop in absolute population using an extended version of a previously published simulation method. Case study 2 uses this refined simulation method to test for a settlement gap identified in oral historical records of descendant Tsimshian First Nations communities from the Prince Rupert Harbour region of the Pacific Northwest region of British Columbia, Canada. Using a regional database of n = 523 radiocarbon dates, we find a significant drop in relative population using the extended simulation-based method consistent with Tsimshian oral records. We conclude that our technical refinement extends the utility of radiocarbon simulation methods and can provide a rigorous test of demographic predictions derived from a range of historical sources.

The Role of Small Villages in Northern Tsimshian Territory From Oral and Archaeological Records

Small villages have been central to progressive models of hunter-gatherer-fisher complexity on the Northwest Coast as a stage in the narrative of increasingly nonegalitarian social relations. We argue that Tsimshian settlement history is more complicated. We examine settlement and chronological data for 66 village sites in the Tsimshian area, 22 of which we define as small. Small villages were present in the area as early as 6500 years ago, but they are also contemporary with larger settlements until after 1300 years ago. We suggest that small villages represent a traditional Tsimshian social entity known as the wilnat’aał, or lineage, knowledge of which is preserved in Tsimshian oral records. We argue that the persistence of this settlement and community form illustrates the foundational role of this social unit throughout Tsimshian history, a result that has implications for archaeological research in the context of Indigenous history.

Archaeological Survey of Dynamic Coastal Landscapes and Paleoshorelines: Locating Early Holocene Sites in the Prince Rupert Harbour Area, British Columbia, Canada

ABSTRACT We present and test a predictive archaeological survey model that targets early Holocene paleoshorelines in the Prince Rupert Harbour area using LiDAR bare earth digital terrain models and a 15,000-year reconstructed history of relative sea level change. Despite a century of archaeological research in the study area, no sites dating earlier than 6000 cal b.p. had been identified prior to our research. Our field survey identified three early Holocene sites associated with paleoshorelines 7–10 m above current sea level (masl). These locations demonstrate repeated use through the Holocene even as shoreline position changes. We discuss these new data in relation to the early Holocene archaeological record from the rest of the northern Northwest Coast and suggest that the region was ubiquitously occupied by this time and that the lack of recorded early Holocene sites in some areas is likely a result of survey and preservation bias, rather than historical reality.

ESTIMATING MARINE RESERVOIR EFFECTS IN ARCHAEOLOGICAL CHRONOLOGIES: COMPARING ΔR CALCULATIONS IN PRINCE RUPERT HARBOUR, BRITISH COLUMBIA, CANADA

The best method for quantifying the marine reservoir effect (MRE) using the global IntCal Marine13 calibration curve remains unresolved. Archaeologists frequently quantify uncertainty on MRE values as errors computed from single pairs of marine-terrestrial radiocarbon ages, which we argue significantly overstates their accuracy and precision. Here, we review the assumptions, methods, and applications of estimating MRE via an estimate of the additional regional offset between the marine and terrestrial calibration curves (ΔR) for the Prince Rupert Harbour (PRH) region of British Columbia, Canada. We acknowledge the influence on ΔR of MRE variation as (1) a dynamic oceanographic process, (2) its variable expression in biochemical and geochemical pathways, and (3) compounding errors in sample selection, measurement, and calculation. We examine a large set of marine-terrestrial pairs (n = 63) from PRH to compare a common archaeological practice of estimating uncertainty from means that generate an uncertainty value of ±49 years with a revised, more appropriate estimate of error of ± 230 years. However, we argue that the use of multiple-pair samples estimates the PRH ΔR as 273 ± 38 years for the last 5,000 years. Calculations of error that do not consider these issues may generate inaccurate age estimates with unjustifiable precision. El mejor método para cuantificar el efecto reservorio marino (MRE, por sus siglas en inglés) usando la curva global de calibración IntCal Marine 13 permanece sin resolver. Los arqueólogos frecuentemente cuantifican la incertidumbre en valores del MRE como errores calculados a partir de pares únicos de edades radiocarbónicas marinas y terrestres que, sostenemos, sobrevaloran significativamente su exactitud y precisión. Aquí revisamos las suposiciones, métodos y aplicaciones para estimar el MRE a través de una estimación de la compensación regional adicional entre las curvas de calibración marinas y terrestres (ΔR) para la región de Prince Rupert Harbour (PRH) en Columbia Británica, Canadá. Reconocemos la influencia sobre el ΔR de variaciones del MRE como (1) un proceso oceanográfico dinámico, (2) su expresión variable en caminos bioquímicos y geoquímicos que producen muestras para datación 14C por AMS y (3) errores compuestos en la selección de muestras, mediciones y cálculos. Examinamos un amplio conjunto de pares marinos-terrestres (n = 63) procedentes de PRH para comparar la práctica arqueológica común de estimar la incertidumbre a partir de promedios que generan un valor de incertidumbre de ±49 años, con una estimación de error revisada, más apropiada, de ±230 años. Este acercamiento estima el ΔR de PRH en 273 ± 38 años para los últimos 5,000 años. Los cálculos de error que no consideran estas cuestiones pueden generar estimaciones inexactas de edad con precisiones injustificables.

Assessing the Scale and Pace of Large Shell-Bearing Site Occupation in the Prince Rupert Harbour Area, British Columbia

ABSTRACT Methodological advancements in geoarchaeology and spatial and chronological modeling are opening new avenues to interpreting large coastal shell-bearing sites. We document the developmental histories of two such sites around Prince Rupert Harbour, Canada, using systematic percussion coring, intensive radiocarbon dating, and 3D surface mapping with Total Station and LiDAR. We also re-analyze a third site (Boardwalk/GbTo-31) excavated and radiocarbon dated in the 1960s, 1970s, and early 2000s using archival field notes, site maps, and stratigraphic profiles georectified using LiDAR. We map the natural landform beneath the sites and document the degree to which people physically modified landforms through the deposition of massive shell accumulations. We model site development through time and space and use accumulation rates and OxCal modeling to test for intentional deposition events. All three sites demonstrate complex and heterogeneous occupation histories. At each we identify instances of very rapid deposition that effectively terraced and extended parts of the natural landform to create places for constructing houses, though these episodes take place within longer histories of slower quotidian deposition. The anthropogenic modifications to the coastline in this area are the result of these mixed processes associated with long histories of occupation.