摘要
沁水盆地石炭纪-二叠纪海陆过渡相含煤岩系发育明显的旋回性,这些沉积旋回与天文周期信号有良好的对应关系。本研究基于古气候替代指标自然伽马(GR)测井数据,通过Acycle软件进行时间序列分析,识别其中的天文周期信号,并建立经405 ka长偏心率校准的天文年代标尺。根据频谱分析确定出沁水盆地4个钻孔剖面晚石炭世至早二叠世的405 ka长偏心率周期、92.4~128.7 ka的短偏心率周期、33.5~48.1 ka的地轴斜率周期以及19.7~23.2 ka的岁差周期,这些周期参数与石炭纪-二叠纪天文轨道旋回周期相近,说明相关沉积记录受到地球轨道周期的驱动。根据天文轨道周期约束的浮动天文年代标尺,可将区内含煤岩系沉积时限约束在6.9 Ma。对层序地层格架和年代标尺的综合分析表明,沁水盆地本溪组顶界沉积年龄为300.00 Ma,太原组沉积年龄为300.00~295.28 Ma,山西组为295.28~293.95 Ma,据此计算出的层序1沉积时限为1500 ka,沉积速率约为2.7 cm/ka,该时期主要发育潟湖及滨外碳酸盐陆棚相;层序2沉积时限为4070 ka,沉积速率约为3.0 cm/ka,该时期沉积相以潮坪、潟湖及滨外陆棚为主,并向三角洲相过渡;层序3沉积时限为1330 ka,沉积速率3.7 cm/ka,发育三角洲相。沉积速率总体呈现逐渐加快的趋势,且海陆过渡相地层沉积速率较海相地层快。本研究建立的天文年代标尺可为区内含煤岩系古环境演化分析提供高分辨率的年代地层格架。
The Permo-Carboniferous marine-continental transitional facies coal-bearing series in Qinshui Basin(35°40'~37°20'N,111°10'~112°45'E)was developed with obvious cyclicities which shows a good correspon-dence with the astronomical periodic signals.Based on the natural gamma(GR)logging data which have been regarded as paleoclimate proxy,we used the Acycle software to perform the time series analysis on the coal-bearing series.The astronomical period signals were identified and the floating astronomical timescales were established.According to the spectral analysis,the 405 ka long eccentricity period,92.4~128.7 ka short eccentricity period,33.5~48.1 ka obliquity period,and 19.7~23.2 ka precession period of the late Carboniferous-early Permian were determined.These periods are similar to the Permo-Carboniferous astronomical orbital cycles proposed by previous researchers,indicating that the relevant sedimentary records were driven by the Earth's orbital periods.According to the floating astronomical timescales constrained by astronomical orbital periods,the sedimentary time range of the coal-bearing series in the Qinshui Basin were constrained to 6.9 Ma.By combination of the sequence stratigraphic framework and the astronomical timescale,the age of the top boundary of Benxi Formation in Qinshui Basin was constrained as 300.00 Ma,the age range of Taiyuan Formation was 300.00~295.28 Ma,and the age range of Shanxi Formation was 295.28~293.95 Ma.The calculated time for sequence 1(Benxi formation and lower part of Taiyuan Formation)was 1500 ka,with the sedimentation rate being about 2.7 cm/ka,and the lagoon and offshore carbonate continental shelf facies were mainly developed during this period.The calculated time for sequence 2(middle and upper Taiyuan Formation)was 4070 ka,with the sedimentation rate being about 3.0 cm/ka,and the sedimentary facies during this period were mainly tidal flats,lagoons and offshore carbonate shelf,being transitioned to delta facies.The calculated time for sequence 3(Shanxi Formation)was 1
作者
褚江曼
刘亮亮
邵龙义
周家民
陈平
白建平
CHU Jiangman;LIU Liangliang;SHAO Longyi;ZHOU Jiamin;CHEN Ping;BAI Jianping(College of Geoscience and Surveying Engineering,China University of Mining and Technology(Beijing),Beijing 100083;State Key Laboratory of Coal and Coalbed Methane Co-mining,Jincheng 048000,Shanxi;CNPC Bohai Drilling Engineering Company Limited,Tianjin 300457;Shanxi Blue Flame Coalbed Methane Engineering Research Co.,Ltd.Jincheng 048000,Shanxi)
出处
《第四纪研究》
CAS
CSCD
北大核心
2023年第6期1513-1525,共13页
Quaternary Sciences
基金
山西省科技计划揭榜招标项目(批准号:20201101004)资助。
关键词
石炭纪-二叠纪
海陆交互相
高分辨率层序地层
天文年代标尺
沉积速率
Permo-Carboniferous
marine-continetal transitional facies
high-resolution sequence stratigraphy
astronomical time scale
rate of sedimentation
