古近系研究新进展

介绍国际地层委员会古近系分会在全球界线层型剖面和点位( GSSP)工作上的新进展和我国陆相古近系分阶情况。中国陆相古近系分为8个阶:上湖阶(下古新统)、池江阶(上古新统)、岭茶阶(下始新统)、卢氏阶(中始新统下部)、垣曲阶(中始新统上部)、蔡家冲阶(上始新统)、乌兰布拉格阶(下渐新统)和塔本布鲁克阶(上渐新统)。其中,白垩系-古近系界线、古新统-始新统界线和始新统-渐新统界线与国际上相应界线接近或一致。近来,在湖南衡东地区获得碳同位素负向漂移的数据,使得该剖面可与新近国际地层委员会批准的伊普里斯阶层型剖面对比,其余各个阶的界线缺少磁性地层学和同位素地层学的证据,同时也有待于国际上“金钉子”的确立

A BRIEF INTRODUCTION TO RECENT ADVANCE IN THE PALEOGENE STUDIES

This paper introduces the new progress in the work on Global Stratotype Sections and Points (GSSPs) made by the International Subcommission on Paleogene Stratigraphy (ISPS) and the efforts to establish the continental Paleogene Stages in China. The continental Paleogene of China includes 8 stages: Shanghuan (lower Paleocene), Chijiangian (upper Paleocene), Lingchan (lower Eocene), Lushian (lower middle Eocene), Yuanquan (upper middle Eocene), Caijiachongian (upper Eocene), Wulanblagean (lower Oligocene), and Tabenbulukian (upper Oligocene). The boundaries between the Upper Cretaceous and Paleogene, Paleocene and Eocene, and Eocene and Oligocene in China nearly accord with corresponding ones elsewhere in the world. The new data on negative carbon isotope excursion obtained recently from the Paleogene strata of Hengdong area, Hunan Province, make it possible to compare the section with stratotype section of the Ypresian Stage, which was approved recently by International Commission on Stratigraphy (ICS). The other boundaries of the stages need the data on magnetic stratigraphy and isotope stratigraphy and await the establishment of international “golden spike”.