下扬子区早三叠世风暴沉积及其特征

<正> 早三叠世,下扬子区为位于华北古陆与华夏古陆之间的陆表海,其中发育一套以碳酸盐岩为主的海相沉积物。近年来,笔者在该区(图1)工作期间,发现在早三叠世时,沿皖南到苏南的广大区域内,风暴沉积作用产生的特征十分显著,风暴岩广为发育。

Character of ternpestites (storm deposit) in the Lower Triassic of the Lower Yangtze Region

During the early Triassic time, there were a great deal of tempesitites along southern Anhui to Jiangsu (or the lower Yangtze region).The tempesitites are characterized by pot casts, multidirectional scoured puddles, graded structures, hummocky cross-stratification or hummocky cross-lamination, chrysanthemum-like structures, special trace fossils facies (on or in sediments of fair weather deposits), and varied sequences of storm deposits.On the basis of analysing the characters of tempesitites, the paper discusses briefly the palaeogeography and palaeoenvironment.