塔里木盆地北缘白垩系——古近系界线研究

Cretaceous-Paleogene boundary on the northern margin of the Tarim Basin

白垩系—古近系界线,亦即中生界—新生界界线,是全球最重要的地质界线之一。塔里木盆地北缘的这一界线,由于上白垩统是否存在、巴什基奇克组和塔拉克组的时代等问题存在较大分歧一直悬而未决。本文通过对巴什基奇克组和塔拉克组首次发现的钙质超微化石、化学地层学及事件地层学等的研究,确定了本区上白垩统的存在,并将白垩系—古近系的界线置于巴什基奇克组与塔拉克组之间。

The Cretaceous-Paleogene boundary,i.e.the Mesozoic-Cenozoic boundary,is one of the most important bound-aries in the world.Owing to the existence of divergent views as to whether there exists the Upper Cretaceous and the ages of the Bashijiqik and Talak formations,this boundary on the northern margin of the Tarim basin is still pending.Based on the discovery of calcareous nannofossils in the Bashijiqik and Talak formations and chemostratigraphic and event stratigraphic studies,it has been determined that there exists the Upper Cretaceous in the area,and the Cretaceous-Paleogene boundary is placed between the Bashijiqik Formation and Talak Formation.