黑龙江东部早白垩世生物地层学研究的主要进展

巴列姆期的菊石、巴列姆期—阿尔必期的海相双壳类、早白垩世的沟鞭藻、放射虫和有孔虫等的发现 ,均证实了黑龙江东部含煤地层龙爪沟群、鸡西群和大架山组的时代为早白垩世中、晚期。鸡西群中含有热河或威替姆动物化石群中常见的双壳类化石 ,这一事实似乎暗示着中国热河或俄罗斯威替姆动物化石群为早白垩世时代。早白垩世 ,特别是巴列姆期—阿尔必期 ,沿大架山—云山—虎林-裴德—鸡西一线北东东方向存在着一条向东 (古太平洋 )开口 ,但由东向西变浅的狭长海湾。多次海侵和海泛沿着这一海湾由东向西至鸡西后向南和向北 ,并可能向西扩散。正是这一海湾和海平面的升降控制着东北地区的早白垩世的气候、地理、生物群落的演变、甚至煤的聚集和油的形成

MAJOR ACHIEVEMENTS IN STUDYING THE EARLY CRETACEOUS BIOSTRATIGRAPHY OF EASTERN HEILONGJIANG

The recognition of the Barremian ammonites, Barremian Albian marine bivalves, Early Cretaceous dinoflagellates, radioralians, and foraminifers has all demonstrated that the coal bearing measures, the Longzhaogou and Jixi Groups, and Dajiashan Formation of eastern Heilongjiang are the middle and late Early Cretaceous age. Jixi Group yields bivalve fossils of Johel or Vitium fossil Fauna, which seems to imply that the age of the Johel fossil Fauna of China and Vitium Fauna of Russia is the Early Cretaceous rather than the Jurassic. There existed an embayment opening into the paleo Pacific and shallowing westward along the line of Dajiashan Yunshan Hulin Peide Jixi in eastern Heilongjiang during the Early Cretaceous, particularly during the Barremian Albian. Marine transgression and sea flooding happened many times along the embayment from east to west, and the sea water spread north and southward and even probably westward from Jixi Basin. It is the change of the embayment and sea level that controlled the evolution of climate, geography and biota, and even the accumulation of coal and the formation of oil of northeast China.