吉林东南部白山盆地下白垩统鹰嘴砬子组时代厘定及地质意义

Determination of Lower Cretaceous Yingzuilazi Formation in Baishan Basin in southeastern Jilin,China and its geological significance

对鹰嘴砬子组层型剖面进行了重新测制,系统采集了古生物化石。研究证明该组所产脊椎动物、无脊椎动物、植物和孢粉化石组合与Eosestheria-Epicharmeropsis-Lycoptera (EEL)组合为代表的热河生物群一致,代表了中国最东部的热河生物群化石产地,地质时代应为早白垩世,而不是前人划归的晚侏罗世。孢粉学和年代地层学研究资料进一步表明,鹰嘴砬子组地质时代应为早白垩世Hauterivian-Barremian期。鹰嘴砬子组区域上可与辽西义县组、冀北大店子组—西瓜园组及龙江盆地光华组对比。

The stratotype profile of Yingzuilazi Formation is measured anew and the paleontological fossils are discovered and gathered. The fossil assemblage comprising vertebrates,invertebrates,plants and sporopollen is in accordance with the Jehol Biota represented by the Eosestheria-Epicharmeropsis-Lycoptera( EEL) assemblage,representing one of the easternmost Jehol Biota localities in China. Thus the geological age of the Yingzuilazi Formation should be assigned to the Early Cretaceous,rather than the Late Jurassic previously. Evidence of palynology and chronostratigraphy further indicate that the geological age of Yingzuilazi Formation should be assigned to Cretaceous Hauterivian-Barremian. The Yingzuilazi Formation can be correlated with the Yixian Formation of western Liaoning,the Dadiangzi and Xiguayuan formations of northern Hebei and the Guanghua Formation of the Longjiang Basin regionally.