F A R Wrangel Island
Iceland
Svalbard
India
Far Eastern Russia
Little Diomede Island
Ellesmere Island
Kamchatka
Cosmogenic Isotope
Research
Quaternary Research
Center
The
Extent and Chronology of Glaciation in the Anadyr Region of Chukotka, Far
Eastern Russia
The field party rafted down the Tanyurer River
in order to map the glacial geomorphology and collect samples for cosmogenic
isotope analysis
U-shaped valley north of Rocamaha Lake,
Koryak Mountains
Ice-moulded bedrock which dates 73 ka using 36Cl
cosmogenic isotope dating
Principal Investigators
Dr. Lyn Gualtieri, Quaternary Research Center, University of Washingtonlyn4@u.washington.edu
Dr. Julie Brigham-Grette, Department of Geosciences, University of Massachusetts
Dr. Olga Glushkova, Northeast Interdisciplinary Scientific Research Institute, Magadan, Russia
Funding
National Science FoundationNational Park Service
Geological Society of America
Department of Geosciences, University of Massachusetts
Project Summary
This work was part of my PhD dissertation at the University
of Massachusetts where I worked with Dr. Julie Brigham-Grette.Field evidence in the Koryak Mountains/Lake Mainitz region of far eastern Russia supports three Pleistocene glacial advances. The early Wisconsinan and pre-Wisconsinan glaciations are represented by broad lobate moraines extending up to 30 km north of the Koryak Mountains. Field evidence demonstrates that the terminal, lateral, and medial moraines, as well as meltwater channels, dead ice topography, kettles and outwash plains mark the extent of ice during the last glacial maximum (LGM), during which glaciers reached no more than 20 km beyond their present limits. Those emanating from the southern Koryak Mountains may have reached the Bering Sea. Numerical and relative dating techniques support these results and test the theoretical models of the LGM in western Beringia. Erratics on moraines and glaciofluvial terraces, common to all valleys at 13-13.8 m above river level (arl), yield 36Cl exposure ages ranging from 10.08 - 25.78 36Cl ka. The Koryak Mountains/Lake Mainitz record of glaciation is spatially and temporally consistent with the glaciation pattern across central Beringia found in other terrestrial and marine records. Glacier growth in the Koryak Mountains was sustained by possible increased summer sea surface temperatures and precipitation in the Northwest Pacific region. Evidence from the northern Koryak Mountains (64° N, 177° E) indicates that the extent of ice in western Beringia was limited to mountain and valley glaciers during the LGM. This field-based research contradicts Grosswald’s (1998) theoretical Beringian Ice Sheet hypothesis.
Publications resulting from this research
Brigham-Grette, J., Gualtieri, L., Glushkova, O.Y., Hamilton, T., Mostoller, D., and Kotov, A. 2003. Chlorine-36 and 14C Chronology Support a Limited Last Glacial Maximum Across central Chukotka, Northeastern Siberia, and No Beringian Ice Sheet. Quaternary Research 59 (3): 386-398.Gualtieri, L., Glushkova, O., and Brigham-Grette, J. 2000. Evidence for restricted ice extent during the last glacial maximum in the Koryak Mountains of Chukotka, far eastern Russia. Geological Society of America Bulletin 112 (7): 1106-1118.
Glushkova, O. and Gualtieri, L. 1998. Features of late Pleistocene Glaciation of the Northern Koryak Uplands. In Environmental Changes in Beringia during the Quaternary. Edited by K.V. Simakov. Magadan: NEISRI FEB RAS. p. 112-133. [in Russian].
Gualtieri, L. 1998. A Field-based Numerical Chronology of Glaciation in Far Eastern Russia. Geological Society of America Program with Abstracts. Toronto, Ontario, Canada.
Links
Department of Geosciences, University of MassachusettsBeringian research at UMASS