大杨树盆地中部甘河地区含被子植物化石地层新知

NEW FINDINGS OF THE ANGIOSPERM-BEARING STRATA IN GANHE,CENTRAL DAYANGSHU BASIN, INNER MONGOLIA,NE CHINA

大杨树盆地位于大兴安岭北段,最近在该盆地中部的内蒙古鄂伦春自治旗甘河地区发现大量保存精美的被子植物化石。通过区域地质调查、火山岩和碎屑岩中锆石测年和生物地层对比等手段,确定这些化石产出层位是上白垩统嫩江组1段,时代位于Santonian晚期—Campanian早期之间,属于松花江生物群分子。这些被子植物化石的发现对研究白垩纪被子植物谱系发生和生态学具有重要意义。

Recently a lot of well-preserved fossil angiosperms were found in Ganhe area of the central Dayangshu Basin,Oroqen Autonomous Banner,Inner Mongolia,NE China.A regional geological survey of this region,geochronological analysis of volcanic and clastic rocks and a biostratigraphic correlation reveal that the fossil-bearing strata belong to the first member of Upper Cretaceous Nenjiang Formation,having an age between the late Santonian and the early Campanian,and that these angiosperms can be assigned to the Songhuajiang Biota.These fossils are of great significance in further understanding the phylogenetic evolution and ecology of Cretaceous angiosperms.