摘要
对重庆市南川区三泉镇宝塔组进行连续而高密度的碳、氧同位素和牙形刺采样与分析。分析结果显示,碳同位素值及曲线形态与晚奥陶世凯迪期碳同位素正漂移事件Gutternberg Inorganic Carbon Excursion (GICE)一致,并显示出的三个次级峰值。宝塔组自下而上发育牙形刺:Protopangerodus insculptus带和Hamarodus brevirameus带。通过与四川盆地及周缘地区其他剖面宝塔组碳同位素曲线的对比,发现GICE事件在不同剖面发育程度不完全一致,南部发育较北部更全,宝塔组起始沉积时间有差异。通过与湖北、安徽、塔里木盆地、北美和瑞典地区的对比,认为中扬子地区宝塔组可能发育不完全;塔里木盆地其浪组与四川盆地宝塔组可对比;再次证实GICE事件具有全球性属性,其多次波动的特征可能与地球古海洋环境变化和奥陶纪生物大辐射有密切关系。
Continuous and high density δ^13 C and δ^18 O isotope and conodonts samples have been collected from the Pagoda Formation at the Sanquan section, Nanchuan, Chongqing, China. The results showed that the carbon isotope curve was consistent with global carbon excursion event Gutternberg Inorganic Carbon Excursion(GICE) in Late Ordovician Katian Stage and its three signal peaks. Two conodonts zones Hamarodus brevirameus zone and Protopangerodus insculptus zone from the bottom to the top have been identified in the Pagoda Formation. Carbon isotope characteristics of other sections in the Sichuan Basin and its adjacent area were used to correlate with Sanquan section. It is achieved that the growth level of GICE is different in this area.The South developed more completely than the North and the Pagoda Formation started to deposit at different times. Furthermore, Hubei, Anhui, Tarim Basin, North America and Sweden were used to correlate with Sanquan section as well. It is obtained that the Pagoda Formation probably does not develop completely in Middle Yangtze region and Qilang Formation in Tarim Basin is comparable with Pagoda Formation. GICE is a global event and the fluctuation is closely related to paleoceanic environment change and the Great Ordovician Biodiversification Event(GOBE).
作者
马雪莹
卢远征
罗忠
樊茹
李鑫
邓胜徽
MA Xue-ying;LU Yuan-zheng;LUO Zhong;FAN Ru;LI Xin;DENG Sheng-hui(Research Institute of Petroleum exploration & development,Petro China,Beijing 100083;State Key Laboratory of Enhanced Oil Recovery,Beijing 100083;Key Laboratory of Oil and Gas Reservoir,CNPC,Beijing 100083)
出处
《地层学杂志》
CSCD
北大核心
2019年第1期18-27,共10页
Journal of Stratigraphy
基金
中国石油天然气股份有限公司"十三五"重点项目(2016A-0206)
国家重大专项(2017ZX05001)
国家自然科学基金(41702031)
关键词
碳同位素地层
地层对比
牙形刺
宝塔组
奥陶系
四川盆地
carbon isotope stratigraphy
stratigraphy correlation
conodont
Pagoda Formation
Ordovician
Sichuan Basin
