Detrital Zircon U-Pb Geochronologyof Sinian–Cambrian Strata in the Eastern Guangxi Area, China  

作　　者：Ruxin Ding Heping Zou Kyoungwon Min Feng Yin Xiaodong Du Xuxuan Ma Zhangxin Su Wenjie Shen 

机构地区：[1]School of Earth Science and Geological Engineering,Sun Yat-sen University, Guangzhou 510275, China [2]Guangdong Provincial Key Laboratory of Mineral Resources & Geological Processes, Guangzhou 510275, China [3]Department of Geological Sciences, University of Florida, Gainesville, FL 32611, USA [4]Exploration Branch Company, SINOPEC, Chengdu 610041, China [5]Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China

出　　处：《Journal of Earth Science》2017年第2期295-304,共10页地球科学学刊（英文版）

基　　金：jointly supported by the National Natural Science Foundation of China (No.41102131);the Fundamental Research Funds for the Central Universities of China (No.12lgpy22);Guangdong Natural Science Foundation (No.2015A030313193);China Geological Survey (No.1212011121064);Chinese Association for science and technology project (No.2014XSJLW01-02);China Scholarship Council

摘　　要：The Eastern Guangxi area locates in the southwestern part of the transition zone between Yangtze and Cathaysia blocks, which is an important region because the boundary between two blocks probablycrosses there. We determined LA-ICPMS U-Pb ages for detrital zircons extracted from three sandstone samples in the Sinian-Cambrian strata in this region. The resulting ages are in the range of the Archeozoic and Neoproterozoic, with three notable concentrates at 991 Ma, 974 Ma, and 964 Ma, all of which are coeval to the Grenvillian magmatic activity. The new age distribution is similar to the data reported in the Precambrian strata of the adjacent southwestern Cathaysia Block, suggesting that most of our detrital zircons are likely derived from the Cathaysia Block. Combined with others＇ research, we are more inclined to accept the opinion that there was not an ocean basin between the two blocks during the Sinian-Cambrian period in Eastern Guangxi area if the timing of collision is the Early Neoproterzoic. But if the timing of collision is the Early Paleozoic, we conclude that Luzhai uplift（i.e., the uplift between Guilin-Yongfu faultand Lipu fault） beyond the west of Dayaoshan regoin might be one part of southwestern sedimentation boundary of Cathaysia Block and Yangtze Block. We also get a few of detrital zircons with ages of ~590 Ma which probably sourced from northeastern Gondwana and 13 detrital zircons with over 3 000 Ma U-Pb ages which record the early formation of the earth.The Eastern Guangxi area locates in the southwestern part of the transition zone between Yangtze and Cathaysia blocks, which is an important region because the boundary between two blocks probablycrosses there. We determined LA-ICPMS U-Pb ages for detrital zircons extracted from three sandstone samples in the Sinian-Cambrian strata in this region. The resulting ages are in the range of the Archeozoic and Neoproterozoic, with three notable concentrates at 991 Ma, 974 Ma, and 964 Ma, all of which are coeval to the Grenvillian magmatic activity. The new age distribution is similar to the data reported in the Precambrian strata of the adjacent southwestern Cathaysia Block, suggesting that most of our detrital zircons are likely derived from the Cathaysia Block. Combined with others＇ research, we are more inclined to accept the opinion that there was not an ocean basin between the two blocks during the Sinian-Cambrian period in Eastern Guangxi area if the timing of collision is the Early Neoproterzoic. But if the timing of collision is the Early Paleozoic, we conclude that Luzhai uplift（i.e., the uplift between Guilin-Yongfu faultand Lipu fault） beyond the west of Dayaoshan regoin might be one part of southwestern sedimentation boundary of Cathaysia Block and Yangtze Block. We also get a few of detrital zircons with ages of ~590 Ma which probably sourced from northeastern Gondwana and 13 detrital zircons with over 3 000 Ma U-Pb ages which record the early formation of the earth.

关 键 词：Cathaysia Block Yangtze Block eastern Guangxi area detrital zircon U-Pb dating 

分 类 号：P597.3[天文地球—地球化学] P535[天文地球—地质学]