|
|||||
|
|
Geochemical Constraints for the Genesis of Post-collisional Magmatism and the Geodynamic Evolution of the Northern Taiwan Region |
|
| Authors: | WANG KUO-LUNG; CHUNG SUN-LIN; O'REILLY SUZANNE Y; SUN SHEN-SU; SHINJO RYUICHI; CHEN CHANG-HWA |
| Institution: | 1 DEPARTMENT OF GEOSCIENCES, NATIONAL TAIWAN UNIVERSITY, PO BOX 13-318, TAIPEI 106, TAIWAN 2 ARC NATIONAL KEY CENTRE FOR THE GEOCHEMICAL EVOLUTION AND METALLOGENY OF CONTINENTS (GEMOC), DEPARTMENT OF EARTH AND PLANETARY SCIENCES, MACQUARIE UNIVERSITY, SYDNEY, N.S.W. 2109, AUSTRALIA 3 16 GIFFEN CLOSE, HOLT, CANBERRA, A.C.T. 2615, AUSTRALIA 4 DEPARTMENT OF PHYSICS AND EARTH SCIENCES, UNIVERSITY OF THE RYUKYUS, OKINAWA, JAPAN 5 INSTITUTE OF EARTH SCIENCES, ACADEMIA SINICA, PO BOX 1-55, NANKANG, TAIPEI, TAIWAN |
| Abstract: | Taiwan is an active mountain belt created by the oblique collisionof the northern Luzon arc with Asia. Late Pliocene extensionalcollapse of the northern Taiwan mountain belt (NTMB) was accompaniedby magmatism that formed the Northern Taiwan Volcanic Zone (NTVZ;2·8–0·2 Ma). The geochemical characteristicsof the NTVZ magmas can thus provide constraints both for themantle source composition and the geodynamic processes operatingin the late orogenic stage of the region. The NTVZ volcanicrocks consist dominantly of calc-alkaline andesites and basalts,along with subordinate but heterogeneous lavas including low-K,shoshonitic and ultrapotassic magmas. From the NE to the SWin the NTVZ, the magmas show systematic compositional variationsfrom low-K to calc-alkaline and then shoshonitic. This spatialgeochemical variation, characterized by southwesterly increasein potassium and incompatible trace elements, appears to besubparallel to the southwestern part of the modern Ryukyu subductionsystem. Sr–Nd isotope ratios of the NTVZ volcanic rocks(87Sr/86Sr |
| Keywords: | : Northern Taiwan Volcanic Zone post-collisional magmatism Pb isotopes subduction components geodynamics of basalt genesis |
| 本文献已被 Oxford 等数据库收录！ | |