DOI: 10.1016/j.palaeo.2015.05.026
论文题名: Paleoproductivity and organic matter sources in Late Quaternary Lake Ontario
作者: Hladyniuk R. ; Longstaffe F.J.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2015
卷: 435 起始页码: 13
结束页码: 23
语种: 英语
英文关键词: Carbon isotopes
; Lake Ontario
; Late Quaternary climate change
; Organic matter sources
; Ostracodes
; Paleoproductivity
英文摘要: We have examined δ13C of ostracode valves and clam shells, carbon and nitrogen mass accumulation rates (C- and N-MAR), atomic C/N and δ13COM from Lake Ontario since ~16,000cal BP to evaluate the impacts of the Laurentide Ice Sheet (LIS) and regional paleohydrology on primary lacustrine productivity and sources of OM. Samples were obtained from piston cores from each of the Niagara, Mississauga and Rochester basins, which geographically span Lake Ontario from west to east. During the glacial period, variations in inputs directly from the LIS versus up-stream glacial Lake Algonquin and (or) ancient Lake Erie controlled the DIC pool in ancestral Lake Ontario. Cold and dry conditions limited primary productivity in the Ontario basin (low C/N ~7.5). Increased contributions of glacial meltwater from glacial Lake Algonquin during the latter stages of deglaciation provided a uniform supply of DIC to ancestral Lake Ontario and other lakes then occupying the Huron and Erie basins, stabilizing the δ13CDIC pool at ~-4‰ (VPDB).Upon hydrologic closure of early Lake Ontario at the onset of post-glacial conditions (12,300cal BP), a growing divergence between the δ13C of ostracode valves (decreases to -6‰) and clam shells (increases to +1‰) indicates differences in summer versus spring DIC pools. The end of glacial meltwater input to early Lake Ontario also made it possible to detect changes in primary lacustrine productivity using the isotopic and C/N proxies. Increasing δ13COM (from ~-29 to -27.5‰) and low C/N (<10) during post-glacial times across Lake Ontario generally support rising primary lacustrine productivity during hydrologic closure and following return to overflow conditions after 8300cal BP. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68858
Appears in Collections: 过去全球变化的重建
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作者单位: The University of Western Ontario, Department of Earth Sciences, London, ON, Canada
Recommended Citation:
Hladyniuk R.,Longstaffe F.J.. Paleoproductivity and organic matter sources in Late Quaternary Lake Ontario[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2015-01-01,435