沙特赛尼亚特矿床赛尼亚特磷块岩段地质特征和层序地层分析  

Geological Characteristics and Sequence Stratigraphy Analysis of the Thaniyat Phosphorite Member in Thaniyat Deposit,Saudi Arabia

作　　者：李治兴[1] 李子颖[1] 秦明宽[1] 王鹏 范洪海 蔡煜琦[1] 衣龙升[1] 张云龙 李国臣[1] 张康[1] 郭邦杰[3] LI Zhixing;LI Ziying;QIN Mingkuan;WANG Peng;FAN Honghai;CAI Yuqi;YI Longsheng;ZHANG Yunlong;LI Guochen;ZHANG Kang;GUO Bangjie(CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China;China Institute of Nuclear Information&Economics,Beijing 100048,China;National Key Laboratory of Remote Sensing Information and Image Analysis Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院、中核集团铀资源勘查与评价技术重点实验室,北京100029 [2]中国核科技信息与经济研究院,北京100048 [3]核工业北京地质研究院、遥感信息与图像分析技术国家级重点实验室,北京100029

出　　处：《铀矿地质》2023年第2期265-276,共12页Uranium Geology

基　　金：沙特阿拉伯磷块岩型铀钍资源调查与评价项目(编号:地技ST1703);中国核工业地质局地勘费项目“中国铀成矿区划及找矿部署研究”(编号:202143-5);“红杂色砂岩后生蚀变机理成矿模拟实验”(编号:202246-6)联合资助。

摘　　要：沙特赛尼亚特矿床是新特提斯磷块岩成矿域的重要组成部分,具有丰富的磷资源及其伴生的铀资源,但是目前对赛尼亚特矿床研究程度较弱。文章在综合分析前人已有工作的基础上,对赛尼亚特矿床及外围开展地质和放射性调查,对赛尼亚特磷块岩段开展实测、矿物学研究、沉积环境和层序地层分析,认为赛尼亚特矿床赛尼亚特磷块岩段中间燧石层为区内含铀磷块岩发育的标志层,并且据此将赛尼亚特磷块岩段分为上部磷块岩层和下部磷块岩层。赛尼亚特磷块岩段及单个磷块岩层内均具有明显的自下而上砂质组分逐步减少而钙质组分增加的特点。磷块岩结构、构造表明其为远距离搬运形成的产物,铀的富集与磷块岩发育密切相关。层序对比分析结果表明,在白垩纪图赖夫期,区域上发育向东南方向的海侵,为研究区再搬运沉积磷块岩的形成提供了动力。赛尼亚特磷块岩段为海侵演化阶段的产物,磷块岩代表层序地层中的海侵体系域,磷块岩沉积结束达到最大海侵面。磷块岩段中间夹杂的泥岩和燧石及顶部燧石层为高位体系域产物,每一层磷块岩代表一次海侵过程,多层磷块岩表明经过几次海侵过程。文章建立的磷块岩层序旋回及动力学模型,对含铀磷块岩型铀资源预测具有重要意义。The Thaniyat deposit in Saudi Arabia is an important part of the Neo-Tethys phosphorite metallogenic domain,which is rich in phosphorus and uranium-bearing phosphorite resources.However,the research on the Thaniyat deposit is quitely weak.In this paper,based on comprehensive analysis of previous work,geological and radiological survey of the Thaniyat deposit and its surrounding areas were carried out,field measurement,mineralogical study,sedimentary environment and sequence stratigraphic analysis of the Thaniyat phosphorite were conducted.The results showed that the chert bed in the middle of the Thaniyat deposit was a marker bed for the development of uranium-bearing phosphorite in the area.The Thaniyat phosphorite member was divided into upper and lower phosphorite beds.From the bottom to the top of the Thaniyat phosphorite member,and the individual phosphorite beds are characterized by a gradual decrease of sandy components and the increase of calcareous components.The texture and structures of the phosphorite indicate that it is a sediment formed by long-distance transportation.The enrichment of uranium is closely related to the phosphorite.Sequence stratigraphic analysis showed that the southeastward transgression occurred in the region during the Turayf Group of the Cretaceous,which provided the driving force for the formation of retransported sedimentary phosphorites in the study area.the Thaniyat phosphorite was the product of marine transgression.Phosphorites represent transgressive system tracts in sequence stratigraphy,and phosphorites reach the maximum transgressive surface at the end of phosphorites sedimentation.The mudstone and chert in the middle of the Thaniyat phosphorite member and the top chert layer are the products of highstand system tract.At the same time,each layer of the phosphorite represents a process of transgression,the multiple layers of phosphorite showed that the process of transgression has undergone several times.The established sequence cycle and dynamic model of phosphorite ar

关 键 词：地质特征 地层结构 矿物学 层序地层 赛尼亚特矿床 

分 类 号：P619.2[天文地球—矿床学] P619.14[天文地球—地质学]