DOI: 10.1016/j.quascirev.2014.01.005
Scopus记录号: 2-s2.0-84893351575
论文题名: A 31,000 year record of paleoenvironmental and lake-level change from Harding Lake, Alaska, USA
作者: Finkenbinder M.S. ; Abbott M.B. ; Edwards M.E. ; Langdon C.T. ; Steinman B.A. ; Finney B.P.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2014
卷: 87 起始页码: 98
结束页码: 113
语种: 英语
英文关键词: Alaska
; Climate change
; Lake sediment geochemistry
; Lake-level
; Late-Quaternary
; Paleolimnology
Scopus关键词: Accelerator mass spectrometry
; Alaska
; Coarse-grained sediments
; Lake level fluctuations
; Lake sediments
; Lake-level
; Late quaternary
; Paleoenvironmental change
; Biogeochemistry
; Biological materials
; Carbon
; Climate change
; Isotopes
; Lakes
; Lead
; Magnetic susceptibility
; Mass spectrometry
; Organic compounds
; Paleolimnology
; Quartz
; Sediments
; clastic sediment
; concentration (composition)
; correlation
; deflation
; fluvial deposit
; lake ecosystem
; lithology
; paleoclimate
; paleoenvironment
; sediment chemistry
; sediment core
; silica
; water depth
; Alaska
; United States
英文摘要: Physical and geochemical proxy analyses of sediment cores from Harding Lake in central Alaska are used to reconstruct paleoenvironmental change and millennial scale fluctuations in lake level for the last ~31,000 years. We analyzed a composite 422cm core from the lake depocenter (42.1m water depth) and identified 4 distinct lithologic units based on variability in dry bulk density, organic matter, biogenic silica, carbon to nitrogen mass ratios (C/N), organic matter carbon isotopes (δ13C), pollen, and elemental abundances via scanning X-ray fluorescence, with age control provided by 16 Accelerator Mass Spectrometry radiocarbon dates and 210Pb dating. In addition, we analyzed a transect of cores from 7.1m, 10.75m, 15.91m, and 38.05m water depths to identify lake level fluctuations and to characterize sediment compositional changes as a function of water depth. Organic matter content and magnetic susceptibility values in surface sediments from all transect cores show a strong correlation with water depth. Interpretation of four lithologic units with well-dated contacts produced a record of water-depth variations that is consistent with independent climate records from eastern Beringia. Basal coarse-grained sediments (quartz pebble diamicton) were deposited prior to 30,700 calendar years before present (yr BP), possibly from fluvial reworking or deflation during a period of severe aridity. Unit 1 sediments were deposited between 30,700 and 15,700yr BP and are characterized by a low organic matter content, a high magnetic susceptibility, and low biogenic silica concentrations resulting from very low lake levels, low terrestrial and in-lake productivity and a high flux of clastic sediment. An abrupt increase in organic matter and biogenic silica concentration marks the transition into Unit 2 sediments, which were deposited between 15,700 and 9,400yr BP when lake levels were higher and variable (relative to Unit 1). The transition to full interglacial conditions at 9,400yr BP marks the beginning of Unit 3. Here an abrupt increase in the sedimentation rate, organic matter and biogenic silica concentration occurs (along with a corresponding decrease to low magnetic susceptibility). These high values persist until 8,700yr BP, signifying a rapid rise to higher lake levels (in comparison to Units 1 and 2). Unit 4 sediments were deposited between 8,700yr BP to 2010 AD and generally contain high concentrations of organic matter and biogenic silica with low magnetic susceptibility, suggesting that lake levels were relatively high and stable during the middle to late Holocene. © 2014 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/60373
Appears in Collections: 过去全球变化的重建
There are no files associated with this item.
作者单位: Geology and Planetary Science, University of Pittsburgh, Pittsburgh, PA 15260, United States; Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom; Alaska Quaternary Center, University of Alaska-Fairbanks, Fairbanks, AK 99775, United States; Department of Meteorology and Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, United States; Department of Biological Sciences, Idaho State University, Pocatello, ID 83209, United States; Department of Geosciences, Idaho State University, Pocatello, ID 83209, United States
Recommended Citation:
Finkenbinder M.S.,Abbott M.B.,Edwards M.E.,et al. A 31,000 year record of paleoenvironmental and lake-level change from Harding Lake, Alaska, USA[J]. Quaternary Science Reviews,2014-01-01,87