DOI: 10.1016/j.gloplacha.2013.05.016
论文题名: A 70,000 year multiproxy record of climatic and environmental change from Rano Aroi peatland (Easter Island)
作者: Margalef O. ; Cañellas-Boltà N. ; Pla-Rabes S. ; Giralt S. ; Pueyo J.J. ; Joosten H. ; Rull V. ; Buchaca T. ; Hernández A. ; Valero-Garcés B.L. ; Moreno A. ; Sáez A.
刊名: Global and Planetary Change
ISSN: 0921-8256
出版年: 2013
卷: 108 起始页码: 72
结束页码: 84
语种: 英语
英文关键词: Holocene
; Last Glacial Maximum
; Marine Isotope Stage 3
; Peat geochemistry
; South Pacific paleoclimate
; Stable isotopes
; X-ray fluorescence core scanner
Scopus关键词: Holocenes
; Last Glacial Maximum
; Marine isotope stages
; Paleoclimates
; Stable isotopes
; X ray fluorescence
; Biogeochemistry
; Biological materials
; Exploratory geochemistry
; Glacial geology
; Isotopes
; Organic compounds
; Stratigraphy
; Vegetation
; Water levels
; Peat
; anticyclone
; C3 plant
; C4 plant
; climate variation
; detritus
; environmental change
; Holocene
; hydrological change
; isotopic composition
; Last Glacial Maximum
; marine isotope stage
; mire
; organic matter
; paleoclimate
; peatland
; Pleistocene
; proxy climate record
; reconstruction
; sedimentation rate
; stable isotope
; storm track
; vegetation dynamics
; westerly
; X-ray fluorescence
; Easter Island
; Pacific Ocean
; Pacific Ocean (South)
英文摘要: The Rano Aroi mire on Easter Island (also known as Rapa Nui; 27°09'S, 109°27'W, 430m above sea level) provides a unique non-marine record in the central South Pacific Ocean for reconstructing Late Pleistocene environmental changes. The results of a multiproxy study on two cores from the center and margin of the Rano Aroi mire, including peat stratigraphy, facies analysis, elemental and isotope geochemistry on bulk organic matter, X-ray fluorescence (XRF) core scanning and macrofossil analysis, were used to infer past water levels and vegetation changes. The chronology was based on 18 14C AMS dates for the upper 8.7m. The extrapolated age for the base of the sequence is 70kyr, which implies that this record is the oldest paleolimnological record on Easter Island. The recovered Rano Aroi sequence consists of a radicel peat formed primarily from the remains of sedges, grasses and Polygonaceae that have accumulated since Marine Isotopic Stage (MIS) 4 (70kyr BP) to the present. From 60 to 40kyr BP (MIS 3), high precipitation/runoff events were recorded as organic mud facies with lighter δ13C, low C/N values and high Ti content, indicating higher detritic input to the mire. A gradual shift in δ13C bulk organic matter from -14% to -26%, recorded between 50 and 45calkyr BP, suggests a progressive change in local peat-forming vegetation from C4 to C3 plant types. Post-depositional Ca and Fe enrichment during sub-aerial peat exposure and very low sedimentation rates indicate lower water tables during Late MIS 3 (39-31calkyr BP). During MIS 2 (27.8-19calkyr BP), peat production rates were very low, most likely due to cold temperatures, as reconstructed from other Easter Island records during the Last Glacial Maximum (LGM). Geochemical and macrofossil evidence shows that peat accumulation reactivates at approximately 17.5calkyr BP, reaching the highest accumulation rates at 14calkyr BP. Peat accretion decreased from 5.0 to 2.5calkyr BP, coinciding with a regional Holocene aridity phase. The main hydrological and environmental changes in Rano Aroi reflect variations in the South Pacific Convergence Zone (SPCZ), Southern Westerlies (SW) storm track, and South Pacific Anticyclone (SPA) locations. © 2013 Elsevier B.V. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880394834&doi=10.1016%2fj.gloplacha.2013.05.016&partnerID=40&md5=8b1ef34686950831080f00d6e8a3ea83
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/11162
Appears in Collections: 全球变化的国际研究计划
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作者单位: Institute of Earth Sciences Jaume Almera CSIC, Lluís Solé i Sabarís s/n, E-08028 Barcelona, Spain
Recommended Citation:
Margalef O.,Cañellas-Boltà N.,Pla-Rabes S.,et al. A 70,000 year multiproxy record of climatic and environmental change from Rano Aroi peatland (Easter Island)[J]. Global and Planetary Change,2013-01-01,108.