DOI: 10.1016/j.palaeo.2011.12.019
论文题名: Holocene climate and seasonality of shell collection at the Dundas Islands Group, northern British Columbia, Canada-A bivalve sclerochronological approach
作者: Hallmann N. ; Burchell M. ; Brewster N. ; Martindale A. ; Schöne B.R.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2013
卷: 373 起始页码: 163
结束页码: 172
语种: 英语
英文关键词: Oxygen isotopes
; Paleoenvironment
; Saxidomus gigantea
; Seasonality
英文摘要: To analyze environmental changes and the seasonality of shell collection in British Columbia during the Holocene, oxygen isotopes were measured from modern and archeological (1337-7438calyr BP) shells of the butter clam Saxidomus gigantea. 1697 discrete isotope samples were taken from two modern and 27 archeological shells with a high temporal resolution (sub-seasonal up to daily). Archeological shells were collected from five shell midden sites on the Dundas Islands Group, northern British Columbia, Canada. The oxygen isotope data reveal clear annual cycles, with the most positive δ18Oshell values occurring during the cold season (slower growth, annual growth line formation) and the most negative δ18Oshell values during the warm season (period of faster growth). Whereas the most positive δ18Oshell values remained relatively constant throughout the Holocene, the warm season δ18Oshell values reflected considerable variability. Summer values observed in the early and late Holocene became approximately 1‰ more negative around 2500-3000 and 5500-6000 BP, implying lower salinity during the Mid-Holocene. Variations in the oxygen isotopic composition of marine shells reflect changes in temperature and salinity. Such large changes in δ18Oshell are unlikely being caused by temperature changes alone. Furthermore, the large annual δ18Oshell amplitude of 3.29-6.56‰, which corresponds to a temperature range of 14.5-29.0°C, exceeds the local annual temperature range by 2.5-17.0°C (0.58-3.85‰). The shell isotope record was also compared with other proxy archives, such as pollen, lake sediments and chironomid communities. The climate changes reflected in the δ18Oshell record match well with environmental changes reported for British Columbia. In addition to the climate information outline above, details about the season of shell collection by the occupants of Dundas Islands can also be obtained from the oxygen isotope and sclerochronological analyses of shells. The oxygen isotope profiles reveal that the archeological shells were collected year-round through time, and that there is no difference in the collection pattern between small and large shell midden sites. This is indicative of a multi-seasonal shellfish harvesting as well as long-term variation in occupation patterns at the Dundas Islands. Despite changes in climate over the Holocene, people maintained a consistent pattern of year-round shellfish harvest. The Mid-Holocene transition is also characterized by a number of cultural changes ranging from technological changes to changes in settlement and subsistence practices of hunter-gatherer groups. © 2012 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/69815
Appears in Collections: 过去全球变化的重建
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作者单位: Earth System Science Research Center, Department of Applied and Analytical Paleontology (INCREMENTS), Institute of Geosciences, University of Mainz, Johann-Joachim-Becher-Weg 21, 55128 Mainz, Germany; Department of Anthropology, McMaster University, 1280 Main Street West, Hamilton, ON, L8S 4L9, Canada; Department of Anthropology, University of British Columbia, 6303 NW Marine Drive, Vancouver, BC, V6T 1Z1, Canada
Recommended Citation:
Hallmann N.,Burchell M.,Brewster N.,et al. Holocene climate and seasonality of shell collection at the Dundas Islands Group, northern British Columbia, Canada-A bivalve sclerochronological approach[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2013-01-01,373