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| Titel |
Age and paleomagnetism of the Okhotsk-Chukotka Volcanic Belt (OCVB) near Lake El'gygytgyn, Chukotka, Russia |
| VerfasserIn |
D. B. Stone, P. W. Layer, M. I. Raikevich |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1868-4556
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| Digitales Dokument |
URL |
| Erschienen |
In: Geology, geophysics and tectonics of Northeastern Russia: a tribute to Leonid Parfenov ; Nr. 4 (2009-09-17), S.243-260 |
| Datensatznummer |
250001450
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| Publikation (Nr.) |
 copernicus.org/smsps-4-243-2009.pdf |
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| Zusammenfassung |
| Paleomagnetic results from the upper two thirds of the whole section of the
Okhotsk-Chukotka Volcanic Belt (OCVB) volcanics exposed in the area around
Lake El'gygytgyn, Chukotka yield stable, consistent magnetic vectors and
well-preserved reversed directions. The magnetostratigraphy and
40Ar/39Ar geochronologic data reported here indicate that the
sampled OCVB volcanics were erupted between about 90 and 67 Ma, and show no
significant change in the apparent pole position over that time. The OCVB
extends from northeast China, across Northeast Russia to the Bering Straight.
This belt is made up of both extrusive and intrusive rocks, with the
extrusive rocks and their associated sediments being dominant. The whole belt
important in interpreting the paleogeography of the region because it
overlies many of the accreted terranes of Northeast Russia. Most importantly,
it overlies parts of the Chukotka-Alaska block which is thought to have moved
out of the Arctic Ocean region, as well as terranes accreted from the south.
These latter terranes have been rafted northwards on the paleo-plates of the
Pacific, implying that the present relative paleogeography of all of the
terranes overlain by the OCVB were essentially in place by 67 Ma, and
possibly as early as 90 Ma. However, comparing our paleomagnetic pole
position for the OCVB with those for North America and Eurasia (a proxy for
Siberia) shows a statistically significant displacement of the OCVB pole to
the south west. This implies that not only the OCVB, but the underlying
terranes of northeast Russia, experienced southerly displacement with respect
to the Siberian and North American platforms since the Late Cretaceous. |
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