地质通报Issue(6)：776-787,12.
内蒙古阿拉善地块北缘沙拉扎山晚石炭世岩体地球化学特征与LA-ICP-MS锆石U-Pb年龄
Geochemistry and LA-ICP-MS zircon U-Pb age of Late Carboniferous Shalazhashan pluton on the northern margin of the Alxa Block, Inner Mongolia and their implica-tions
摘要
Abstract
The Wenduermaodao biotite granodiorite pluton is located in Shalazhashan on the northern margin of the Alxa Block. LA-ICP-MS U-Pb dating of zircons from the pluton yielded an age of 301±2Ma, which indicates that the pluton is a Late Carbonif-erous intrusion. According to the geochemical analysis, the Wenduermaodao pluton has high SiO 2 (67.23%~72.57%), K2O(1.14 %~6.13%) and Al2O3(13.67%~17.29%), suggesting that it is calc-alkaline and peraluminous (A/CNK=0.98~1.10). This intrusion has low REE content (38.86×10-6~74.39×10-6) with a relative enrichment of LREE and week Eu anomalies (δEu=0.9~1.3). The primitive mantle normalized trace element patterns are characterized by the enrichment of the LILE (Rb, Th, K) and depletion of HFSE (Nb, Ta, P, Ti), showing the features of I-type granite. Combined with regional geology, the authors hold that the pluton was emplaced in a subduction setting and derived from mixed sources of oceanic crust and juvenile crust, and the subduction of Paleo Asian plate be-neath the northern Alxa Block took place at 301Ma or earlier.关键词
阿拉善/沙拉扎山/晚石炭世/岛弧/LA-ICP-MS锆石U-Pb年龄Key words
Alxa/Shalazhashan/Late Carboniferous/island arc/LA-ICP-MS zircon U-Pb dating分类
天文与地球科学引用本文复制引用
杨奇荻,张磊,王涛,史兴俊,张建军,童英,郭磊,耿建珍..内蒙古阿拉善地块北缘沙拉扎山晚石炭世岩体地球化学特征与LA-ICP-MS锆石U-Pb年龄[J].地质通报,2014,(6):776-787,12.基金项目
中国地质调查局项目 （）
