Discovery of Ancient Volcanoes in the Okhotsk Sea (Russia): New Constraints on the Opening History of the Kurile Back Arc Basin

Geosciences

卷:10

Igor Tararin¹  Folkmar Hauff²  Kaj Hoernle²  Reinhard Werner²  Paul van den Bogaard²  Boris Baranov³ 

[1] Far East Geological Institute RAS, 100-letiya Vladivostoka Prospect 159, 690022 Vladivostok, Russia;

[2] GEOMAR Helmholtz Centre for Ocean Research Kiel, Wischhofstr. 1-3, 24148 Kiel, Germany;

[3] Shirshov Institute of Oceanology, Nakhimovsky Avenue 36, 117851 Moscow, Russia;

关键词: Kurile Basin;    island arc;    back arc spreading;    volcanoes;    geochemistry;    Ar/Ar-age dating;   

DOI  :  10.3390/geosciences10110442

来源: DOAJ

【 摘 要 】

Here we present the first radiometric age and geochemical (major and trace element and isotope) data for samples from the Hydrographer Ridge, a back arc volcano of the Kurile Island Arc, and a newly discovered chain of volcanoes (“Sonne Volcanoes”) on the northwestern continental slope of the Kurile Basin on the opposite side of the arc. The ⁴⁰Ar/³⁹Ar age and geochemical data show that Hydrographer Ridge (3.2–3.3 Ma) and the “Sonne Volcanoes” (25.3–25.9 Ma) have very similar trace element and isotope characteristics to those of the Kurile Island Arc, indicating derivation from a common magma source. We conclude that the age of the “Sonne Volcanoes” marks the time of opening of the Kurile Basin, implying slow back arc spreading rates of 1.3–1.8 cm/y. Combined with published data from the Kurile fore arc, our data suggest that the processes of subduction, Kurile Basin opening and frontal arc extension occurred synchronously and that extension in the rear part and in the frontal part of the Kurile Island Arc must have been triggered by the same mechanism.

【 授权许可】

Unknown