丙南组的新认识

通过攀西地区丙南组露头及典型剖面研究 ,详细论述了丙南组的岩性组合特征及分段 ,首次提出丙南组在部分地区为海相沉积的新观点。丙南组的时代自曾繁礻乃先生 1945年于攀枝花丙南渡命名至今 ,皆因未发现化石而暂置晚三叠世。通过野外实地调查及相关资料研究 ,以古气候因素、与邻区早三叠世青天堡组对比 ,以及丙南组与上覆大荞地组的接触关系等多方面资料 ,提出丙南组的时代归属应为早三叠世。

A NEW KNOWLEDGE OF THE BINGNAN FORMATION

The authors discussed in detail the characteristics of the rock assemblage and inferred paleoenvironment of the deposited Bingnan Formation by studying the outcrop and typical section of the Bingnan Formation in Panxi area. They advances a new viewpoint for the first time that the paleoenvironment of the deposited Bingnan Formation is a marine sedimentary environment in partial region. Before now, many scholars used to refer tentatively the age of Bingnan Formation to Late Trassic Epoch because of no fossils. Now, the age of the Bingnan Formation is first assigned to Early Trassian on the basis of its paleoclimatical data , its correlation with the conterminous Qingtianbao Formation(T 1), and its contact with the overlying Daqiaodi Formation(T 3).