Southern Greenland glaciation and Western Boundary Undercurrent evolution recorded on Eirik Drift during the late Pliocene intensification of Northern Hemisphere glaciation

QUATERNARY SCIENCE REVIEWS

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Article

Blake-Mizen, Keziah^1,2  Hatfield, Robert G.³  Stoner, Joseph S.³  Carlson, Anders E.³  Xuan, Chuang⁴  Walczak, Maureen³  Lawrence, Kira T.⁵  Channell, James E. T.⁶  Bailey, Ian^1,2 

[1] Univ Exeter, Camborne Sch Mines, Penryn Campus,Treliever Rd, Penryn TR10 9FE, Cornwall, England

[2] Univ Exeter, Environm & Sustainabil Inst, Penryn TR10 9FE, Cornwall, England

[3] Oregon State Univ, Coll Earth Ocean & Atmospher Sci, Corvallis, OR 97331 USA

[4] Univ Southampton Waterfront Campus, Natl Oceanog Ctr Southampton, Ocean & Earth Sci, Southampton SO14 3ZH, Hants, England

[5] Lafayette Coll, Dept Geol & Environm Geosci, Easton, PA 18042 USA

[6] Univ Florida, Dept Geol Sci, Gainesville, FL 32611 USA

关键词: Plio-Pleistocene transition;    Northern Hemisphere glaciation;    Paleoclimatology;    Paleoceanography;    Paleomagnetism;    Greenland Ice Sheet;    North Atlantic;    Ice-rafted debris;    Relative paleointensity;   

DOI  :  10.1016/j.quascirev.2019.01.015

来源: Elsevier

【 摘 要 】

We present new sedimentological and environmental magnetic records spanning similar to 3.2-2.2 Ma, during the intensification of Northern Hemisphere glaciation, from North Atlantic Integrated Ocean Drilling Program Site U1307 on Eirik Drift. Our new datasets and their high-fidelity age control demonstrate that while inland glaciers - and potentially also at times restricted iceberg-calving margins - have likely existed on southern Greenland since at least similar to 3.2 Ma, persistent and extensive iceberg-calving glacial margins were only established in this region at 2.72 Ma, similar to 300 kyr later than in northeastern and eastern Greenland. Despite a dramatic increase in Greenland-sourced ice-rafted debris deposition on Eirik Drift at this time, contemporaneous changes in the bulk magnetic properties of Site U1307 sediments, and a reduction in sediment accumulation rates, suggest a decrease in the delivery of Greenland-sourced glaciofluvial silt to our study site. We attribute these changes to a shift in depositional regime from bottom-current-dominated to glacial-IRD-dominated between similar to 2.9 and 2.7 Ma, in response to a change in the depth of the flow path of the Western Boundary Undercurrent relative to our study site. (C) 2019 Elsevier Ltd. All rights reserved.

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