地质通报2023，Vol.42Issue(11)：1894-1908,15.DOI:10.12097/j.issn.1671-2552.2023.11.008
新疆阿尔金喀腊大湾地区拉配泉组流纹岩年龄和地球化学特征及其对阿尔金北缘构造演化的启示
Chronology and geochemical characteristics of the Lapeiquan Formation rhyolite in the Altun Kaladawan area,Xinjiang,and implications for tectonic evolution of the northern margin of Altun
摘要
Abstract
Due to the low level studies on the Altun Lapeiquan Formation in Xinjiang,its depositional age and tectonic genesis are still in doubt.Chronological and geochemical studies were carried out on the rhyolites of the Lapeiquan Formation.The results of zircon LA-ICP-MS U-Pb dating show that the ages of the second and third member rhyolites of the Lapaiquan Formation are 497±2.0 Ma and 483.4±1.9 Ma,respectively.The petrogeochemical studies show that the samples are Si-rich(70.07％～78.55％),Mg-poor(0.32％～0.58％),and Mg#-low(24～30).The rare earth elements exhibit the characteristics of enrichment of light rare earth elements and relatively deficient in heavy rare earth elements((La/Yb)N=10.23～12.73),and the negative Eu is abnormally obvious(δEu=0.10～0.19);the analysis of trace elements shows that the samples are obviously enriched in La,Nd,Zr,Ce,Sm,U,Th,Hf,etc.,and relatively deficient in Sr,Nb,Ti,etc.Combined with the previous researches,the depositional age of the Lapeiquan Formation is determined to be Late Cambrian-Early Ordovician.The second member of rhyolite has the characteristics of A-type granite,and it most likely came from partial melting of crustal materials,and the tectonic environment is a post-arc extensional environment caused by the reversal of the North Altun Ocean.关键词
拉配泉组/流纹岩/U-Pb年龄/地球化学/阿尔金Key words
Lapeiquan Formation/rhyolite/U-Pb dating/geochemistry/Altun分类
天文与地球科学引用本文复制引用
武彬,王爱国,彭博,王继龙,张艺武,鲍晓明,叶现韬,于俊杰..新疆阿尔金喀腊大湾地区拉配泉组流纹岩年龄和地球化学特征及其对阿尔金北缘构造演化的启示[J].地质通报,2023,42(11):1894-1908,15.基金项目
国家科技支撑计划项目《甜水海-塔什库尔干地块基底演化与成矿》(编号:2015BAB05B01-02) （编号:2015BAB05B01-02）
