Skip Navigation



Journal of Petrology Advance Access published online on October 14, 2004
Journal of Petrology, doi:10.1093/petrology/egh065
This Article
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
46/2/221    most recent
egh065v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by OKAMURA, S.
Right arrow Articles by MARTYNOV, Y. A.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Received May 12, 2003
Accepted July 26, 2004

Article

Cenozoic Magmatism of the North-Eastern Eurasian Margin: The Role of Lithosphere Versus Asthenosphere

SATOSHI OKAMURA 1*, RICHARD J. ARCULUS 2, and YURI A. MARTYNOV 3

1 SAPPORO CAMPUS, HOKKAIDO EDUCATION UNIVERSITY, SAPPORO 002-8502, JAPAN
2 DEPARTMENT OF EARTH AND MARINE SCIENCES, AUSTRALIAN NATIONAL UNIVERSITY, CANBERRA, ACT 0200, AUSTRALIA
3 FAR EAST GEOLOGICAL INSTITUTE, VLADIVOSTOK 690022, RUSSIA

* To whom correspondence should be addressed. E-mail: okamura{at}sap.hokkyodai.ac.jp.


  Abstract

Sikhote-Alin and Sakhalin are located in the Russian Far East flank of the northernmost part of the Sea of Japan. Magmatism in this region preceded, was concurrent with, and continued after the extension and sea-floor spreading (25-18 Ma) that formed the Sea of Japan. Among the Sikhote-Alin and Sakhalin volcanic suites, Eocene-Oligocene (55-24 Ma) lavas are characterized by greater large ion lithophile element and rare earth element enrichments compared with Early-Mid-Miocene (23-15 Ma) tholeiites, and also show a depletion in high field strength elements (HFSE). The geochemical characteristics of the Eocene-Oligocene and Early-Mid-Miocene basalts are consistent with migration of the locus of magma generation beneath the Sikhote-Alin and Sakhalin areas from subduction-modified lithospheric mantle into mid-ocean ridge basalt (MORB)-source asthenosphere as spreading in the Sea of Japan progressed. Mid-Miocene-Pliocene (14-5 Ma) lavas, erupted following the opening of the Sea of Japan, include alkaline and sub-alkaline basalts with wide ranges in trace-element abundances, varying between two distinct end-members: (1) volumetrically minor alkaline basalts with Zr-Nb and Sr-Nb-Pb isotope compositions similar to asthenosphere-derived, intra-plate-hotspot basalts from eastern China; (2) more abundant, lithosphere-derived, low-alkali tholeiites depleted in HFSE. The similarity of isotopic signatures coupled with systematically different rare earth element (REE) abundances in the Mid-Miocene-Pliocene and Chinese basalts are best modeled by similar extents of melting of spinel lherzolite and garnet lherzolite, respectively. The Mid-Miocene-Pliocene alkali basalts were generated by small degrees of partial melting of hot asthenosphere beneath a thin lithospheric lid; the thin lithospheric mantle beneath the Sikhote-Alin and Sakhalin region resulted from heating and extension associated with the opening of the Sea of Japan.

Keywords: north-eastern Eurasian margin; Sikhote-Alin-Sakhalin; Japan Sea opening; subcontinental lithosphere; asthenosphere.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 J PetrologyHome page
J.-I. KIMURA and T. YOSHIDA
Contributions of Slab Fluid, Mantle Wedge and Crust to the Origin of Quaternary Lavas in the NE Japan Arc
J. Petrology, November 1, 2006; 47(11): 2185 - 2232.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.