This thesis represents the first example of a pre-agricultural, pre-colonial land disturbance event in the archaeological record of North America. It demonstrates the critical importance of multivariate analysis and µ-XRF core scanning in determining precise chronologies for episodes of heightened clastic input from soil erosion, enhanced by human occupation, shellfish harvesting, and burial mound construction. / Serpent Mounds is a prehistoric (Middle Woodland Period, ca. 2000--1000 BP) burial mound complex located on the north shore of Rice Lake, in southern Ontario, Canada.
The complex includes a 60m long and 10m wide sinuous earthwork ridge interpreted as a serpent effigy and eight smaller oval mound structures.
Archaeological excavations determined seasonal site occupation for harvesting wild rice and shellfish and conducting mortuary rites.
The timing of mound construction and site occupation is poorly constrained by limited radiocarbon dates, restricted to burials.
The site is of high cultural importance as the only known effigy mound structure in Canada and is a sacred First Nations burial ground; thus all investigation must employ non-invasive techniques.
High-resolution XRF Core Scanning and micropaleontologic analysis (testate amoebae) of 12 lake sediment cores was employed to investigate the timing of mound construction, and assess geochemical records of prehistoric land disturbance.
Land disturbance is indicated by increased sediment flux, by rising abundance of minerogenic elements (K, Ti, Zr, Si, Fe) within a distinctive silt-rich gyttja unit.
The event is also recorded in the thecamoebian assemblage, which is dominated by indicators of a eutrophic, turbid lake environment.
Principal Component Analysis and Cluster Analysis of µ-XRF data identify distinctive chemofacies across several cores.
AMS 14C dates for the prehistoric land disturbance episode correspond with the Point Peninsula occupation, indicating a protracted occupation period of \textasciitilde 750 years (2050 - 1300 cal BP) with two major peaks in soil erosion at 1900 and 1450 cal BP.
The sedimentation rate (>1.5mm/yr) during the Middle Woodland phase of enhanced erosion was comparable to that during the 1838 CE dam construction at Hastings.
The reconstructed Middle Woodland paleoshoreline and water levels indicate a shallow lake and wetland environment, with viable habitats for wild rice stands and shellfish resources.
The results demonstrate that XRF Core Scanning and micropaleontological methods are important for the investigation of culturally-sensitive archaeological sites, including sacred burial grounds where conventional archaeological excavation cannot be undertaken. / Thesis / Master of Science (MSc) / Serpent Mounds is a prehistoric (Middle Woodland Period, ca. 2000 - 1000 BP) burial mound complex located in Rice Lake, Ontario.
Archaeological excavation (1897 - 1970) determined the site was occupied by people of the Point Peninsula culture (ca. 2200 - 1350 BP) on a seasonal basis, for burial rites and shellfish gathering.
Many questions remain with regard to the date of mounds construction, how long the site was occupied, and how occupation and construction activities impacted the local environment.
The site has been designated as a National Historical Site and excavation is no longer permitted in the interest of site preservation and cultural value to First Nations.
This study investigated the history of environmental changes associated with prehistoric indigenous and European land use changes using minimally-invasive methods, including sonar bathymetric mapping, XRF Core Scanning and microfossil analysis of lake sediment cores.
Sonar data were employed to map the lake bottom relief (bathymetry) and to reconstruct past changes in lake levels and shoreline positions.
µ-XRF methods measures changes in elemental abundance in lake core samples to identify human occupation phases and land disturbance.
Microfossils (testate amoebae) track the ecosystem response to environmental changes associated with human occupation.
The geochemical and microfossil data identified an interval of increased sediment delivery to Rice Lake, coinciding with the arrival of Point Peninsula peoples.
The land disturbance is recognized in cores by an increase in zirconium (Zr), titanium (Ti) and other soil-derived elements.
During this phase, lake levels rose gradually, wetlands expanded and wild rice was abundant resource available to indigenous peoples.
Following European colonization in the 1820’s, and the construction of the Hastings Dam (1838 CE), lake levels increased rapidly by over \SI{2}{\metre}, causing a shift to a more nutrient-rich (eutrophic) lake environment and a decline in wild rice stands.
Soil erosion associated with European land clearance is recorded by in a dramatic increase in the abundance of soil-derived elements.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/24089 |
| Date | 05 1900 |
| Creators | Pringle, Tynan |
| Contributors | Boyce, Joseph, Earth Sciences |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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