Asia Oceania Geosciences Society (AOGS) 5th Annual Assembly

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Start Date: 
Monday, June 16, 2008
End Date: 
Friday, June 20, 2008

Location: Busan, South Korea

Web: http://www.asiaoceania.org/society/index.asp

Includes the following session:

Session SE59 Post-collision magmatism: plumes versus top-down plate tectonics?

Convenors: M. Flower (flower@uic.edu), N. Hoang (ng.hoang@gmail.com), J. Deng (dengjinfu@21cn.com), X. Mo (mxx@sky.cugb.edu.cn)

As subduction gives way to plate collision, magmatic activity tends to progress from HFSE-depleted calc-alkaline to potassic and ultrapotassic types. These are succeeded by voluminous OIB-like basalts, marking post-collision transtensional ‘nodes’ and possibly reflecting perturbations of ductile sublithospheric mantle. These late-stage magmas are mostly non-potassic and rich in HFSE and include both tholeiites and variably SiO2-undersaturated types. Examples – linked in space and time to recent and ongoing Tethyan collisions – include those in western and eastern Europe, eastern and southeastern Asia, and the Levant and northern Africa. Rarely, strongly potassic types HFSE-rich basalts appear, distinct from the shoshonites and lamproites commonly associated with collisions, examples appearing in NE China, Central Spain, and the western Germany. Geochemical and geophysical studies have led to robust debates, for example, as to whether the basalts reflect deep-sourced plumes or the effects of plate-induced upper mantle displacement. This session will be an opportunity to discuss current models pertaining to subcontinental mantle flow fields in relation to intraplate basalt genesis.

City: 
Busan, South Korea