石炭纪年代地层学研究概况

An Outline of Carboniferous Chronostratigraphy

国际石炭系分会尝试性地将石炭系分成两部分 ,下石炭亚系或 Mississipian及上石炭亚系或 Pennsylvani-an,前者包括 3个统 :Tournaisian,Visean,Serpukhovian;后者包括 4个统 :Bashkirian,Moscovian,Kasimovian以及Gzhelian。由于全球对比的需要 ,西欧和北美的统级年代单位作为辅助性序列也被置于综合年代地层表中。石炭系底界、中间界线及顶界的 GSSP已经分别确立在法国的 L aserre剖面 ,美国的 Arrow Canyon剖面 ,哈萨克斯坦的Aidaralash Creek剖面。据西欧及澳大利亚的同位素年龄数据 ,石炭纪的时间跨度为 5 3 Ma。中国的石炭系划分成丰宁亚系和壶天亚系 ,前者包括岩关统和大塘统以及汤粑沟阶 ,旧司阶 ,上司阶和德坞阶 ;后者包括威宁统和马平统以及罗苏阶 ,滑石板阶 ,达拉阶和小独山阶。

Because of the rapid southward movement of Gondwana towards the end of the Visean and especially during the Namurian, and the development of a substantial icecap which influenced world climates and depositional pattern, the Carboniferous is one of the most difficult parts of the Phanerozoic record in which to establish a timescale of global significance. Up to now, only one GSSP that is the middle Carboniferous boundary was established in the Carboniferous. It becomes acceptable to divide the Carboniferous into two parts, a Lower Carboniferous or Mississippian and an Upper Carboniferous or Pennsylvanian. The former includes Tournaisian, Visean and Serpukhovian, and the latter includes Bashkirian, Moscovian, Kasimovian, and Gzhelian. Two complementary sets of series, which are from West Europe and North America, are preferred by SCCS for the interval between the base of the Namurian/Serpukhovian to the end of the Carboniferous because of extreme provincialism of biota during this interval. A revised Chinese Carboniferous chronostratigraphic chart is composed of two subsystems, four series, and eight stages,namely: the Fengningian and Hutianian subsystems; the Aikuanian, Tatangian, Weiningian, and Mapingian series; and the Tangbagouan, Jiusian,Shangsian,Dewuan,Luouan,Huashibanian, Dalan, and Xiaodushanian stages.