Analysis on the Forming Times and Gravel Fabric of Baiyan Conglomerate

Through statistical studies on identification of pollen samples and conglomerate fabric,as showed by pollen assemblages,the formation time of Baiyan conglomerate was in middle Jurassic,not the Paleogene which was generally considered.As showed by gravel fabric,its origin was littoral or coastal features.Characteristic of diamond in conglomerate showed that it had similar charcterstics with Changma diamond in Mengyin county.Through comprehensive analysis,it is regarded that Baiyan conglomerate was formed in western Shandong in Jurassic before the birth of pull-apart basin.It should be the production before the deposition of Santai formation.Determination of deposition times of Baiyan conglomerate will play an important role in restoring lithofacies paleogeography and determining erosion and transportation of the primary diamond mine.