气候变化领域集成服务门户(CCPortal): Reconciling the onset of deglaciation in the upper Rangitata valley; Southern Alps; New Zealand

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DOI	10.1016/j.quascirev.2018.11.003
	Reconciling the onset of deglaciation in the upper Rangitata valley; Southern Alps; New Zealand
	Barrell D.J.A.; Putnam A.E.; Denton G.H.
发表日期	2019
ISSN	0277-3791
起始页码	141
结束页码	150
卷号	203
英文摘要	Enquiry into the detailed timing of paleoclimate events depends on well-resolved and reliable chronologies. A recently published set of 10Be surface-exposure ages for moraine boulders in the upper Rangitata valley was interpreted to indicate a gradual reduction in glacier surface height between c. 21 and c. 17 ka, without rapid glacier recession beginning c. 18 ka as reported from other valleys. The dating results were suggested to be consistent with moraine geomorphology and an interpreted lack of post-glacial lake formation in the valley. In contrast, we argue that the geomorphology is consistent with sustained glacier recession and we highlight evidence for a post-glacial lake. Furthermore, the upper Rangitata moraine chronology was encumbered by inaccurate altitude values assigned to many of the sample sites. Recalculation of the 10Be ages using accurate elevations produces values that are as much as 3000 years younger than originally reported. The recalculated values indicate no significant age difference across the c. 300-m relative altitudinal spread of sample locations, with mean age of all samples c. 17.7 ± 0.3 ka. The previous inference of slow late-glacial ice retreat is not supported by the recalculated chronology. Rather, the revised glacial chronology implies that substantial ice-surface lowering of the Last Glacial Maximum Rangitata glacier was in progress shortly after c. 18 ka. The revised upper Rangitata chronology is compatible with dating from other eastern valleys of the Southern Alps, indicating moraine formation at c. 18 ka, followed by sustained glacier recession associated with regional climatic amelioration. © 2018 Elsevier Ltd
英文关键词	Beryllium-10; Last glacial termination; Moraine chronology; New Zealand; Paleoclimate
语种	英语
scopus关键词	Geomorphology; Glacial geology; Lakes; Glacial chronology; Glacier recession; Last Glacial Maximum; Last glacial terminations; Moraine chronology; New zealand; Paleoclimates; Surface exposure age; Landforms; beryllium isotope; boulder; chronology; deglaciation; elevation; geomorphology; glacial lake; Last Glacial; Last Glacial Maximum; moraine; paleoclimate; Canterbury [South Island]; New Zealand; Rangitata River; South Island; Southern Alps
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/152073
作者单位	GNS Science, Private Bag 1930, Dunedin, 9054, New Zealand; School of Earth and Climate Sciences and Climate Change Institute, University of Maine, Orono, ME 04469, United States
推荐引用方式 GB/T 7714	Barrell D.J.A.,Putnam A.E.,Denton G.H.. Reconciling the onset of deglaciation in the upper Rangitata valley; Southern Alps; New Zealand[J],2019,203.
APA	Barrell D.J.A.,Putnam A.E.,&Denton G.H..(2019).Reconciling the onset of deglaciation in the upper Rangitata valley; Southern Alps; New Zealand.Quaternary Science Reviews,203.
MLA	Barrell D.J.A.,et al."Reconciling the onset of deglaciation in the upper Rangitata valley; Southern Alps; New Zealand".Quaternary Science Reviews 203(2019).