新近纪海相生物地层事件年龄新编

介绍新近纪海相生物地层研究的新进展。2004年新的"国际地质年代表"以405ka偏心率长周期为基础来划分新近纪的主要地层界线,标志着轨道地层学时代的到来。新生代包括E1—E162偏心率长周期,底界的年龄为65.5±0.3Ma,其中新近纪有E1—E58周期,底界年龄为23.03Ma,并且根据天文调谐得出一系列新的古地磁年龄和生物事件年龄。由于这些新年龄,特别是接近新近纪底部的年龄与早期结果相差0.5Ma或更大,所以将其汇总介绍,以求与当前国际研究保持同步衔接,增强海洋新近纪高分辨率地层工作的准确性。

NEW AGES FOR NEOGENE MARINE BIOSTRATIGRAPHIC EVENTS

This paper introduces new development in the study of marine Neogene stratigraphy.Major stratigraphic boundaries in the international standard chronostratigraphic timescale published in 2004 are drawn on the basis of the 405ka long eccentricity cycles,indicating the arrival of a new era of orbital stratigraphy.In the new timescale,the Cenozoic Era now comprises E1 to E162 long eccentricity cycles,with the base dated at 65.5±0.3Ma,while the Neogene is now composed of E1 to E58 long eccentricity cycles from a base of 23.03Ma.Also obtained from orbital tuning is a series of new ages for paleomagnetic chrons and biostratigraphic events.Because some of these ages(especially those from the lower part of the Neogene) bear a difference of about 0.5Ma or more from earlier estimates,they are being summarized here for the purpose of updating and keeping up with the current international standard,as well as for strengthening the accuracy of high-resolution dating of marine Neogene strata.