贵州平坝白垩纪地层及沉积特征

The Cretaceous Strata and Sedimentary Characters of Pinba,Guizhou

通过对平坝一带区域地质的调查，认为这套白垩系砾岩、紫红色泥岩为山麓—河湖相沉积，是燕山期构造控制的山前盆地沉积。在紫红色泥岩中首次发现介形类Ｔａｌｉｃｙｐｒｉｄｅａｓｐ．、Ｔ．ｌａ－ｔｉｏｖａｔａ、Ｃｙｐｒｉｓｓｐ．，证明其属上白垩统扎佐组，而不是侏罗系。根据沉积学研究将其划分为４种沉积类型，并圈定了各类型空间展布。砾岩，砂岩属碎屑流沉积产物，而紫红色泥岩为湖相沉积，两者在很大程度上属同时异相沉积。

After making a regional geological investigation in Pinba area of Guizhou Province,the authors consider that the conglomerates and the red mudstones are the deposits of piedmont fluviolacustrine facies,being the intermontane basin controlled by tectonics during the Yanshanian Stage.The ostracods ( Talicypridea latiovata,T. sp. and Cypris sp.) are first found in the red mudstones,which are proved to belong to the Late Cretaceous Zhazuo Formation,not being of Jurassic System.It may be divided into 4 sedimentary types.In addition,the grain size analysis of the conglomerates and sandstones shaws that they were the detrital sediments,the red mudstones are the deposits of lake facies,and the conglomerates and the red mudstones are synchronous heteropic deposits to a great extent.