TY - JOUR

T1 - Obliquity forcing of Quaternary glaciation and environmental changes in NE Siberia

AU - Zech, W.

AU - Zech, R.

AU - Zech, M.

AU - Leiber, K.

AU - Dippold, M.

AU - Frechen, M.

AU - Bussert, R.

AU - Andreev, A.

N1 - Funding Information: The authors gratefully acknowledge the financial support by the German Research Foundation (grant Ze 154/52-2 ). We also thank many Russian and German colleagues for collaboration during project preparation, fieldwork and discussion, especially C. Siegert, A. Prokopiev, I. Belolyubsky, V. Spektor, and G. Stauch. U. Hambach analysed magnetic susceptibilities, and T. Engelbrecht prepared the figures. Copyright: Copyright 2011 Elsevier B.V., All rights reserved.

PY - 2011/4/1

Y1 - 2011/4/1

N2 - Reconstructing Quaternary glacial and environmental changes in the vast, high-northern latitudes of Siberia is essential for a better understanding of global past climate variability and its potential solar forcings. Two sediment outcrops in the Dyanushka Valley in the southwestern foreland of the Verkhoyansk Mountains, northeast Siberia, were investigated using a multi-proxy approach (lithostratigraphy, geochemistry, palynology, and radiocarbon and IRSL dating). Three piedmont glaciations reached the outcrop sites. The glacial advances are dated to >140, ∼119-92 and ∼78-53 ka and thus, within dating uncertainties, correspond to obliquity minima during marine isotope stages (MIS) 6, 5d, and 4. This chronology corroborates and refines previous studies that have documented the successively more restricted glacial extents in Siberia during the course of the last glacial cycle. The observed glaciation pattern is out of phase with global ice volume estimates and probably indicates a strong aridisation trend. Additionally, the results show that the geochemical and mineralogical composition of the sediments contains information about provenance. Sediments originating from the Verkhoyansk Mountains are generally enriched in TiO2, MgO, P2O5, Fe2O3, Cr, illite, and chlorite, whereas sediments derived from the Lena River contain more expandable clay minerals, Ba, Sr. Alkane patterns as biomarker proxies turn out to be particularly valuable where poor preservation of pollen is an issue, and, generally speaking, vegetation reconstruction helps distinguishing between 'warm versus cold mode' sediments.

AB - Reconstructing Quaternary glacial and environmental changes in the vast, high-northern latitudes of Siberia is essential for a better understanding of global past climate variability and its potential solar forcings. Two sediment outcrops in the Dyanushka Valley in the southwestern foreland of the Verkhoyansk Mountains, northeast Siberia, were investigated using a multi-proxy approach (lithostratigraphy, geochemistry, palynology, and radiocarbon and IRSL dating). Three piedmont glaciations reached the outcrop sites. The glacial advances are dated to >140, ∼119-92 and ∼78-53 ka and thus, within dating uncertainties, correspond to obliquity minima during marine isotope stages (MIS) 6, 5d, and 4. This chronology corroborates and refines previous studies that have documented the successively more restricted glacial extents in Siberia during the course of the last glacial cycle. The observed glaciation pattern is out of phase with global ice volume estimates and probably indicates a strong aridisation trend. Additionally, the results show that the geochemical and mineralogical composition of the sediments contains information about provenance. Sediments originating from the Verkhoyansk Mountains are generally enriched in TiO2, MgO, P2O5, Fe2O3, Cr, illite, and chlorite, whereas sediments derived from the Lena River contain more expandable clay minerals, Ba, Sr. Alkane patterns as biomarker proxies turn out to be particularly valuable where poor preservation of pollen is an issue, and, generally speaking, vegetation reconstruction helps distinguishing between 'warm versus cold mode' sediments.

UR - http://www.scopus.com/inward/record.url?scp=79951946218&partnerID=8YFLogxK

U2 - 10.1016/j.quaint.2010.04.016

DO - 10.1016/j.quaint.2010.04.016

M3 - Article

AN - SCOPUS:79951946218

VL - 234

SP - 133

EP - 145

JO - Quaternary international

JF - Quaternary international

SN - 1040-6182

IS - 1-2

ER -