华南东部晚古生代岩相古地理及构造指示意义  

Late Paleozoic Lithofacies Paleogeography and Tectonic-sedimentary Evolution of Eastern South China

作　　者：朱孝钰 孙大亥 何文康 陈一铭 李兴一 姚卫华 ZHU XiaoYu;SUN DaHai;HE WenKang;CHEN YiMing;LI XingYi;YAO WeiHua(School of Earth Sciences and Engineering,Sun Yat-sen University,Zhuhai,Guangdong 528478,China;Southern Campus,Lianhua Middle School,Shenzhen,Guangdong 518033,China;Zhejiang Institute of Geological Survey,Hangzhou 311203,China;School of Earth Sciences,Zhejiang University,Hangzhou 310027,China;Guangdong Provincial Key Laboratory of Geodynamics and Geohazards,Zhuhai,Guangdong 528478,China)

机构地区：[1]中山大学地球科学与工程学院,广东珠海528478 [2]深圳市福田区莲花中学南校区,广东深圳518033 [3]浙江省地质调查院,杭州311203 [4]浙江大学地球科学学院,杭州310027 [5]广东省地球动力作用与地质灾害重点实验室,广东珠海528478

出　　处：《沉积学报》2024年第6期1918-1935,共18页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42102117);广东省自然科学基金项目(2020A1515011224,2024A1515010778)。

摘　　要：【目的】经历早古生代武夷—云开造山运动后,华南东部进入晚古生代构造平静期,区域内发生大范围海侵事件并沉积了厚层的上古生界沉积序列。其中,泥盆系—下二叠统空谷阶的地层厚度展布、岩相横向变化等特征对了解华南东部在武夷—云开造山垮塌后的古地貌继承、晚古生代盆地沉降、海平面变化等方面有重要意义。【方法】对区内泥盆纪—早二叠世空谷期地层进行厚度和岩性统计,分别编制了早泥盆世、中泥盆世、晚泥盆世、早石炭世、晚石炭世—早二叠世萨克马尔期、早二叠世亚丁斯克期—空谷期的地层等厚图和平面岩相图,并计算各世期的盆地沉降速率。【结果】武夷—云开造山垮塌之后,华南晚古生代盆地的形成与演化可分为两个阶段。第一阶段发生在泥盆纪时期,华南东部呈东北高、西南低的地势特征,盆地沉降速率大(约25 m/Ma)。第二阶段发生在石炭纪—早二叠世空谷期,构造活动趋于平静,盆地大范围接受海侵,盆地沉降速率小(约10 m/Ma)。【结论】晚古生代盆地发生第一阶段沉降主要受控于构造活动,其构造活动机制主要为武夷—云开造山垮塌,并且与华南板块从冈瓦纳大陆裂离所产生的拉张作用也有一定关联。盆地发生第二阶段沉降主要受控于沉积物负载和气候变化,且晚泥盆世—早石炭世气候变化对盆地沉降的影响较大。[Objectives]Following the Early Paleozoic Wuyi-Yunkai orogeny,eastern South China experienced a tectonically quiescent period in the Late Paleozoic,with large-scale marine transgression and thick sediment deposition.Specifically,the nature of the strata in the Lower Devonian to the Kungurian stage of the Early Permian,such as isopach changes and lateral variation of lithofacies,are important for understanding the post-orogenic topography of eastern South China.[Methods]Stratigraphic thicknesses and lithological data for the region were collected and strata isopach maps and lithofacies maps were compiled for six main epochs/ages:the Early,Middle and Late Devonian,the Early Carboniferous,the Late Carboniferous to the Sakmarian age of the Early Permian,and the Artinskian age to Kungurian age of the Early Permian.The tectonic subsidence rate of the basin at five different localities was calculated for each epoch/age.[Results]The subsidence of the Late Paleozoic basin in eastern South China is divided into two stages:(i)a high subsidence rate(about 25 m/Ma)in the Devonian;and(ii)a low subsidence rate(about 10 m/Ma)in the Carboniferous to Kungurian age of the Early Permian.[Conclusions]Taking the regional widelydistributed and large-scale normal faults into consideration,it is speculated that the first stage of basin subsidence was mainly influenced by tectonic activity inherited from the post-Wuyi-Yunkai orogenic collapse and possibly the separation of South China from Gondwana during the Devonian.The second stage was controlled by the icehouse climate together with the sediment load in the basin during the Carboniferous to Early Permian.

关 键 词：华南 晚古生代 地层等厚图 岩相图 盆地沉降 

分 类 号：P534.4[天文地球—古生物学与地层学]