广东南雄盆地晚白垩世主田组沉积特征及古气候分析  

Sedimentary Characteristics and Paleoclimate Analysis of the Late Cretaceous Zhutian Formation in Nanxiong Basin of Guangdong Province

作　　者：朱蕾蕾 陈留勤[1] 吴文斌 丁婷 ZHU Leilei;CHEN Liuqin;WU Wenbin;DING Ting(School of Earth Sciences,East China University of Technology,Nanchang 330013,China;China State Science Dingshi Environmental Engineering Co.,Ltd.Beijing 100020)

机构地区：[1]东华理工大学地球科学学院,江西南昌330013 [2]中科鼎实环境工程有限公司,北京100020

出　　处：《东华理工大学学报（自然科学版）》2023年第2期132-141,共10页Journal of East China University of Technology(Natural Science)

基　　金：国家自然科学基金项目(41962009);东华理工大学研究生创新基金(DHYC-202130)。

摘　　要：华南白垩系陆相红层发育,为认识特殊的白垩纪温室气候在东亚低纬度的陆地响应提供了重要载体。通过野外剖面观测和样品粒度、色度、碳酸钙含量、磁化率、总有机碳含量等实验,对广东南雄盆地中南部的主田剖面主田组进行沉积环境和古气候研究。研究结果表明,主田组由一套细粒碎屑岩组成,其中的古土壤以发育钙质结核、钙板层、遗迹化石等为识别特征。主田组砂岩样品的碎屑颗粒主要为石英,岩屑和长石次之,多为次棱角至次圆状,分选性较好,颗粒支撑结构,胶结物以钙质和铁质为主。其沉积环境主要为泛滥平原沉积,伴有河流沉积。在白垩纪末期(马斯特里赫特期)古气候总体趋于温凉的背景下,主田组的古气候具有从早期到晚期由湿热向干热转变的趋势。The Cretaceous terrestrial red beds are widely developed in south China,which provide important materials for understanding the continental response to the special Cretaceous greenhouse climate in low latitude areas in east Asia.The sedimentary environment and paleoclimate of the Zhutian Formation in the south-central part of Nanxiong basin,were studied by field section observations and experiments of grain size,chromaticity,calcium carbonate content,magnetic susceptibility and total organic carbon content.The results show that the Zhutian Formation is composed of fine-grained clastic rocks in which and paleosols were identified by the development of carbonate nodules,carbonate deposition horizons,and trace fossils.The sandstone samples from the Zhutian Formation are mainly composed of quartz,small amounts of lithic-fragments and feldspars cemented by calcite and iron oxides.The particles are clast-supported,sub-angular to sub-rounded and well sorted.The field observations and sample experiments suggest that the Zhutian Formation was dominantly deposited in flood plains companied with river environments.Under the bankground of the paleoclimatic change towards warm and cool,the paleoclimate might have changed from humid-hot to dry-hot conditions from the early to late depositional stages of the Zhutian Formation.

关 键 词：晚白垩世 陆相红层 沉积环境 古气候 南雄盆地 

分 类 号：P532[天文地球—古生物学与地层学] P534.53[天文地球—地质学]