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| Titel |
Volcanic ash layers in Lake El'gygytgyn: eight new regionally significant chronostratigraphic markers for western Beringia |
| VerfasserIn |
C. Van den Bogaard, B. J. L. Jensen, N. J. G. Pearce, D. G. Froese, M. V. Portnyagin, V. V. Ponomareva, V. Wennrich |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 10, no. 3 ; Nr. 10, no. 3 (2014-05-23), S.1041-1062 |
| Datensatznummer |
250116977
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| Publikation (Nr.) |
 copernicus.org/cp-10-1041-2014.pdf |
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| Zusammenfassung |
| Ash layers from explosive volcanic eruptions (i.e., tephra) represent isochronous
surfaces independent from the environment in
which they are deposited and the distance from their source. In comparison
to eastern Beringia (non-glaciated Yukon and Alaska), few Plio-Pleistocene
distal tephra are known from western Beringia (non-glaciated arctic and
subarctic eastern Russia), hindering the dating and correlation of sediments
beyond the limit of radiocarbon and luminescence methods. The identification
of eight visible tephra layers (T0–T7) in sediment cores extracted from Lake
El'gygytgyn, in the Far East Russian Arctic, indicates the feasibility of
developing a tephrostratigraphic framework for this region. These tephra
range in age from ca 45 ky to 2.2 My old, and each is described and characterized
by its major-, minor-, trace-element and Pb isotope composition. These data
show that subduction-zone-related volcanism from the
Kurile–Kamchatka–Aleutian Arc and Alaska Peninsula is the most likely
source, with Pb isotope data indicating a Kamchatkan volcanic source for
tephra layers T0–T5 and T7, while a source in the Aleutian Arc is possible
for tephra T6. The location of Lake El'gygytgyn relative to potential source
volcanoes (> 1000 km) suggests these tephra are regionally
distributed over a large area. These deposits provide a unique opportunity
to correlate the high-resolution paleoenvironmental records of Lake
El'gygytgyn to other terrestrial paleoenvironmental archives from western
Beringia and marine records from the western North Pacific and Bering Sea, and
to move towards the development of a robust integrated framework between the
continuous paleoclimatic records of Lake El'gygytgyn and other terrestrial
and marine records in NE Eurasia. |
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