摘要
研究了广西柳桥地区东攀剖面有机碳同位素的组成,并和浙江煤山剖面进行了对比。结果表明东攀剖面在1δ3Corg变化趋势上,既具有全球PTB剖面普遍存在的共性,又具有其独特性。在东攀剖面一个显著的1δ3Corg负漂移出现在事件界线(EB)之上和二叠系/三叠系界线(PTB)之下,这与煤山剖面具有相似性。显著的1δ3Corg负漂移指示了P/T之交生物绝灭后海水表层水原始生产率的降低以及大气和海水中CO2含量的增加,并得到放射虫绝灭事件、火山事件和海退事件的响应。煤山剖面1δ3Corg负漂移从第27层就开始向13C富集的方向恢复,而东攀剖面1δ3Corg在下Induan阶仍持续亏损,表明东攀剖面早三叠世的生物复苏明显滞后于煤山剖面的。
The organic carbon isotope compositions were examined for the first time from a well-preserved deepwater PTB section （Dongpan section） in Liuqiao area, Guangxi. The global correlation comparison is carried out by organic carbon isotope stratigraphy between Dongpan section and GSSP at Meishan section in Zhejiang. There are remarkable similarities and differences between the δ^13Corg trends of both sections. In Dongpan section, a remarkable negative excursion occurs after the onset of ‘PTB events＇ , which is similar to Meishan section, and was accompanied by the mass extinction of radiolarian, volcanic activities and sea level fall. The recovery towards more enriched δ^13Corg values at Meishan section occurs in a zone of bed 27, but continued negative δ^13Corg values throughout the lower Induan in Dongpan section coincide with the marked recovery lag, which is probably related to continuously adverse conditions in the Early Triassic.
出处
《现代地质》
CAS
CSCD
北大核心
2006年第1期42-48,共7页
Geoscience
基金
国家自然科学基金项目(40232025)
关键词
有机碳同位素
二叠系/三叠系界线
深水相
东攀剖面
柳桥地区
广西
organic carbon isotope
Permian/Triassic boundary
deep-water deposit
Dongpan section
Liuqiao area
Guangxi
