摘要:
实测辽宁省建昌县冰沟剖面,选择其为单位层型;开展岩石地层、多门类生物化石和沉积相分析等系统研究,重新厘定陆相阜新阶定义.建昌冰沟组主要由砾岩、砂岩、泥岩和煤层组成,分成三个岩段,第二段为煤系地层.该组为陆相湖盆扇三角洲沉积体系,相序叠置分析属砂砾坝、分流河道、泥沙坪、泥炭沼泽和洪积平原等沉积环境.通过研究以叶肢介为主的化石发生和演变序列,及综合前人研究资料,阜新阶生物地层划分包括叶肢介组合带3个、孢粉化石组合2个、双壳类组合1个和介形虫组合2个.底界层型定在小冰沟村西单一浅湖相地层中,生物标志为叶肢介Orthestheropsis originalis的始现.依据孢粉和介形虫化石资料,阜新阶对比为国际地层表早白垩世巴列姆阶(Barremian)~阿尔必阶(Albian).
Abstract:
Continental stratotypes and definitions of the Fuxinian Stage were stipulated by studying systematically litho-stratigraphy, multi-category fossils and sedimentary facies at Binggou of Jianchang County, Liaoning Province. The Binggou Formation in Jianchang is maily composed of conglomerates, sandstones, mudstones and coal layers and can be divided into three members with coal layers in the 2nd member. Its facies sequence shows a set of lacustrine fan-delta sediments, such as sand-gravel dams, distributary channels, mud-sandy grounds, peat swamps, and flood plains. Many bio-stratigraphic assemblages and zones were distinguished, based on occurrences and evolutionary sequences of fossils and other referential data, i.e., 3 assemblage zones of conchostracan, 2 assemblages of sporo-pollen, 1 assemblage of bivalve and 2 assemblages of ostracodan. The bottom-boundary stratotype of Fuxinian Stage in the West Mountain of Binggou was chosen, and the fossil mark of bottom-boundary is evolutionary occurrence of conchostracanOrthestheropsis originalis Tian (sp. nov.). According to sporo-pollen and ostracodan fossils, the age of Fuxinian could be correlated to the Barremian – the Albian of the National Stratigraphy Standards.
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