中国西部晚第三纪—第四纪有孔虫和钙质超微化石的发现及其地质意义

FRAMWORK OF CAMBRIAN SEDIMENTARY SEQUENCE AND EVOLUTION OF CARBONATE PLATFORM IN NORTH CHINA

报导了中国西北晚中新世—第四纪陆相咸化湖泊介形类群中发现的有孔虫和钙质超微化石组合，并从生态和古地理的角度论证了它们属于非海侵来源，图示了这些生物化石的地理分布。认为由于主要受到干燥气候下咸化湖泊环境的控制，中新世以来，喜盐水生生物群介形类、有孔虫和钙质超微生物等随干旱气候控制的咸化湖泊不断向东扩展。因此，不能笼统地把这些生物化石作为海侵证据。根据地质学现实主义类比原则，提出中国东部早第三纪没有大规模的海侵沉积，丰富的石油天然气资源来自陆相咸化湖泊和深水湖泊沉积。

There are two sets of rock succession developed in Cambrian system of North China. One is marked by alternational deposit between clastic rock and carbonate rock (Xinji Fm. to Xuzhuang Fm.), and another is platform carbonate (Zhangxia Fm. to Fengshan Fm.). Both of them indicate respectively two evolutional stages: devoloping stage and mature stage of carbo￣nate platform. On the basis of the study of lithofacies and facies succession, eight third sequences are discerned in strata of Cambrian, which have different characteristics of facies succession in different stages of carbonate and of stratigraphic accumulation represented by different types of facies succession.