二叠系长兴阶全球界线层型剖面和点位  

THE GLOBAL STRATOTYPE SECTION AND POINT (GSSP) FOR THE BASE OF THE CHANGHSINGIAN STAGE (UPPER PERMIAN)

作　　者：金玉玕[1] 王玥[1] Charles Henderson Bruce R.Wardlaw 沈树忠[1] 曹长群[1] 

机构地区：[1]现代古生物学和地层学国家重点实验室,中国科学院南京地质古生物研究所,江苏南京210008 [2]卡尔加里大学地质与地球物理系 [3]美国地质调查局,美国弗吉尼亚州美国20192

出　　处：《地层学杂志》2007年第2期101-109,共9页Journal of Stratigraphy

基　　金：中国科学院知识创新工程重要方向性项目(KZCX2-YW-122);国家自然科学基金(No.40621062);国家重点基础研究发展计划项目(2006CB806400)。

摘　　要：二叠系乐平统长兴阶底界全球界线层型和点位(GSSP)确立在我国浙江长兴煤山D剖面长兴灰岩的下部、4a-2层之底,以牙形石演化序列Clarkina longicuspidata-C.wangi中C.wangi的首现为标志。该点位位于长兴组底界之上88cm处,与长兴期特征的■类化石Palaeofusulina sinensis和大巴山菊石类的首次出现层位一致。界线层的碳同位素存在明显的负漂移,正磁极性带出现在吴家坪晚期的反极性带之上。在煤山D剖面以西300m处的C剖面出露较多的龙潭组地层,清晰地反映出龙潭组—长兴组连续的沉积序列,被列为辅助层型剖面。The Global Stratotype Section and Point （GSSP） for the base of the Changhsingian Stage is defined at the First Appearance Datum （FAD） of the conodont Clarkina wangi within the lineage from C. longicuspidata to C. wangi at a point 88cm above the base of the Changhsing Limestone in the lower part of Unit 4 （base of Bed 4a-2） at Meishan D section, Changxing County, Zhejiang Province, South China. This level is consistent with the first appearance of the index Changhsingian fusulinid Palaeofusulina sinensis and tapashanitid ammonoids. In addition, the boundary interval is clearly recognizable by the depletion of isotopic carbon ratios and the normal polarity zone appearing above the Late Wuchiapingian reversed polarity zone. Meishan Section C about 300m to the west of Section D exposes more of the upper part of the Lungtan Formation. It clearly shows the transitional nature of deposition across the Lungtan/Changhsing formational boundary, and thus is described as a supplementary reierence section.

关 键 词：二叠系 乐平统 长兴阶 全球界线层型和点位(GSSP) 年代地层 浙江 长兴 

分 类 号：P534.46[天文地球—古生物学与地层学]