Universität zu Köln

Minyuk, P. S., Borkhodoev, V. Y. and Wennrich, V. (2014). Inorganic geochemistry data from Lake El'gygytgyn sediments: marine isotope stages 6-11. Clim. Past., 10 (2). S. 467 - 486. GOTTINGEN: COPERNICUS GESELLSCHAFT MBH. ISSN 1814-9332

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Abstract

Geochemical analyses were performed on sediments recovered by deep drilling at Lake El'gygytgyn in central Chukotka, northeastern Russia (67 degrees 30' N; 172 degrees 05' E). Major and rare element concentrations were determined using X-ray fluorescence spectroscopy (XRF) on the <250 mu m fraction from 617 samples dated to ca. 440 and 125 ka, which approximates marine isotope stages (MIS) 11 to 6. The inorganic geochemistry indicates significant variations in elemental composition between glaciations and interglaciations. Interglacial sediments are characterized by high contents of SiO2, Na2O, CaO, K2O, and Sr and are depleted in Al2O3, Fe2O3, TiO2, and MgO. An extreme SiO2 enrichment during MIS 11.3 and 9.3 was caused by an enhanced flux of biogenic silica (BSi). The geochemical structure of MIS 11 shows similar characteristics as seen in MIS 11 records from Lake Baikal (southeastern Siberia) and Antarctic ice cores, thereby arguing for the influence of global forcings on these records. High sediment content of TiO2, Fe2O3, MgO, Al2O3, LOI, Ni, Cr, and Zr typifies glacial stages, with the most marked increases during MIS 7.4 and 6.6. Reducing conditions during glacial times are indicated by peaks in the Fe2O3 content and coinciding low Fe2O3/MnO ratios. This conclusion also is supported by P2O5 and MnO enrichment, indicating an increased abundance of authigenic, fine-grained vivianite. Elemental ratios (CIA, CIW, PIA, and Rb/Sr) indicate that glacial sediments are depleted in mobile elements, like Na, Ca, K and Sr. This depletion was caused by changes in the sedimentation regime and thus reflects environmental changes.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Minyuk, P. S. UNSPECIFIED UNSPECIFIED UNSPECIFIED Borkhodoev, V. Y. UNSPECIFIED UNSPECIFIED UNSPECIFIED Wennrich, V. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-450444
DOI:	10.5194/cp-10-467-2014
Journal or Publication Title:	Clim. Past.
Volume:	10
Number:	2
Page Range:	S. 467 - 486
Date:	2014
Publisher:	COPERNICUS GESELLSCHAFT MBH
Place of Publication:	GOTTINGEN
ISSN:	1814-9332
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language CHEMICAL-WEATHERING INDEXES; LATE PLEISTOCENE; CLIMATE-CHANGE; MAGNETIC-SUSCEPTIBILITY; CORE PG1351; GRAIN-SIZE; RECORD; BAIKAL; VARIABILITY; ROCKS Multiple languages Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/45044