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

• Main Authors: Satoshi Okamura, Richard J. Arculus, Yuri A. Martynov
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2003
• Subjects: KEY WORDS; north-eastern Eurasian margin; Sikhote-Alin–Sakhal; Sion; Sakhalin
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.596.5653; http://petrology.oxfordjournals.org/content/46/2/221.full.pdf

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 exten-sion and sea-floor spreading (25–18Ma) that formed the Sea of Japan. Among the Sikhote-Alin and Sakhalin volcanic suites, Eocene–Oligocene (55–24Ma) lavas are characterized by greater large ion lithophile element and rare earth element enrichments compared with Early–Mid-Miocene (23–15Ma) 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 (14–5Ma) lavas, erupted fol-