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Geochemical Characteristics and Tectonic Significance of Triassic Granite from Taer Region, the Northern Margin of West Kunlun
Author(s) -
Jianguo HUANG,
Ruidong YANG,
Jian YANG,
Chunlong CUI
Publication year - 2013
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12055
Subject(s) - geology , crust , zircon , terrane , geochemistry , lithology , tectonics , mantle (geology) , continental crust , petrology , paleontology
Late Hercynian‐early Indosinian (Triassic) granite is widely distributed around the Taer region of the northern margin of West Kunlun. The rock mass is mainly composed of calcalkaline porphyroid biotite adamellite and characterized by SiO 2 ‐rich, high‐Ca, moderate‐alkaline, and strongly peraluminous attributes, and relatively low ΣREE with LREE enrichment and a moderate Eu anomaly. As shown in the trace element spider web diagram, distinct peaks appear for Th, La, Nd, and Zr and clearly low values appear for Ba, Nb, Sr, P, and Ti. Further, compared with the primitive mantle, Rb/Sr and Rb/Ba are considerably higher and Nd/Th and Nb/Ta are relative low, all falling into the scope of the crust‐origin rocks, indicating the characteristics of the crust‐origin S‐type granite. The rock mass's zircon U‐Pb isotopic age is determined to be 235.7 ± 3.9 Ma. On the basis of the age data, spatio‐temporal location, lithology, and geochemistry of the rock mass, we conclude that the formation of the rock mass is closely related to the strong compressional orogenic movement (240 Ma) of the Tianshuihai terrane and the South Kunlun terrane. The rock mass is the product of the collision orogenic movement. However, distinct differences are observed between the studied rock mass and the synorogenic Bulunkou rock mass, which may be caused by the different collision strength and different positions with respect to the collision zone.