松辽盆地中白垩世海侵事件质疑

Doubts about the validity of the Middle Cretaceous transgression in Songliao basin.

松辽盆地中白垩统松花江生物群中含沟鞭藻、钙质超微化石等海相起源生物的属种及海绿石矿物。海源生物具有低分异度、低丰富度的特点，且与典型陆相生物叶肢介、轮藻共生，而海绿石矿物则广泛见于登娄库组至明水组，其成分具有高铝、低铁、低钾特点。在综合分析国内外近年来陆相沉积盆地中有关沟鞭藻、有孔虫、钙质超微化石等海源生物及海绿石矿物研究成果的基础上，对松辽盆地中白垩统海源生物和海绿石矿物的海相性提出了质疑。结合围岩地球化学特征及岩相古地理资料，认为海源生物和海绿石矿物的出现代表了大型封闭古咸化湖环境，它们的存在不能作为海侵的证据。松辽盆地中白垩统丰富的石油资源来自陆相咸化湖泊和深水湖相沉积。

number of marine ancestry genera and species such as Dinoflagellates, Calcareous nannofossils, and glauconite minerals are discussed in Sungari Biota of the Middle Cretaceous in Songliao basin. The marine ancestry organisms which are characterized by a low diversity and low abundance are coexist with some typically continental organisms such as Conchostraca, Chara, etc.. Glauconite minerals which are characterized by a highAl, lowFe and lowK are widely distributed from Denglouku Formation to Mingshui Formation in Songliao basin. Based on the new studies of Dinoflagellates, Foraminifera, Calcareous nannofossils and glauconite minerals of other terrestrial basins at home and abroad n the latest years, the authors query the validity of marineindicators of the marine ancestry organisms and glauconite minerals in Songliao basin. Their occurrence represents a biota in a largeclosed salinized lake according to the studies of the geochemical index, sedimentary faces and palaeogeography. Their existence can not be considered as a criteria of sea transgression. Abundant petroleum resource of the Middle Cretaceous in Songliao basin come from the continental salinized lake and deep lake deposits.