In order to determine the age attribution and tectonic setting of the volcanic strata of the Manketou’ebo Formation in the Dongwuqi area of Inner Mongolia, the geochronological characteristics and geochemical characteristics of the rhyolite of the Manketou’ebo Formation were studied. The rhyolite of zircon harmony is good, and the age-weighted average of 206 Pb/238 U is 150.9±4.2 Ma, which is the product of the Late Jurassic magma evolution event. The element geochemical characteristics show that the rhyolite in the Manketou’ebo Formation belongs to the high-potassic calc-alkaline series of rocks and is characterized by high silicon, alkali-rich, highaluminum, and low-calcium-depleted magnesium. The total amount of rare earth elements changes greatly, the distribution curve is right-turned, and there is negative anomaly of Eu.It enriches Large Ion-Litophilic Elementsof Rb, K, Th, and LREE, Simultaneously depleteselementsof Sr, Nb, Ti, P.The basic compatible elements Cr, Co, Ni and Mg# are relatively low, rhyolite has A-type granite characteristics, and the magma is derived from the partial melting of the lower crust rocks. Combined with regional research data, the formation of the Late Jurassic rhyolite in the study area is closely related to the lithospheric extension environment after the land-continent collision in the Mongolia-Okhotsk suture zone. Its chronological and geochemical results provide a powerful basis for exploring the closure time of the Mongolia-Okhotsk Ocean in the southern Daxinganling region.
类型: 国际会议
作者: YIN Zhigang,GONG Zhaomin,ZHANG Shengting,WANG Guanqun,ZHANG Zhihao,ZHOU Xiaogang
来源: 第九届世界华人地质科学研讨会 2019-06-01
年度: 2019
分类: 基础科学
专业: 地质学,地质学,地质学
单位: Mining Institute of Liaoning Technical University
分类号: P588.14;P59;P548
DOI: 10.26914/c.cnkihy.2019.028330
页码: 97
总页数: 1
文件大小: 57k
下载量: 1
本文来源: https://www.lunwen66.cn/article/635243449501ea98a7209369.html