• 责任者：Geng Yuansheng (Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Liu Yongqing
• 刊名：Acta Geologica Sinica
• 出版年：2012
• 卷期：86(9)
• 关键词：中元古代 ; Mesoproterozoic ; 扬子地台 ; Yangtze Platform
• 页码：p.1479-1490
• 图表：6 illus., 1 table, 43 refs.
• 分类号：0801
• issnNo：ISSN0001-5717
• isbnNo：CN11-1951/P

The Tong’an Formation is part of the folded basement in the southwestern margin of Yangtze Craton and further subdivided into five lithological units. Thus, the geochronology of the Tong’an Formation was estimated between ～1.8 Ga to 1.5 Ga based upon the newly obtained U-Pb age result. The zircon ages of 1 513 Ma and 1 531 Ma from gabbro diorite dyke are consistent with the previous data of (1 503± 17) Ma from volcanic tuff of the Heishan Formation in the Dongchuan Group, which suggests that gabbro-diorite dyke intruding the Tong’an Formation and volcanic tuff from Heishan Formation in the Dongchuan Group belongs to the same magmatic cycle. The third lithological unit of the Tong’an Formation is proposed to be correlated with the Heishan Formation of the Dongchuan Group in Yunnan Province.