松辽盆地南部DL地区含铀地层层序沉积特征及演化  

Sequence Sedimentary Characteristics and the Evolution of Uranium-bearing Stratigraphy in the Southern DL Area of Songliao Basin

作　　者：唐国龙 姜山[1] 余弘龙 王常东[1] 黄笑 刘庆 杨志亮[1] 武飞[1] TANG Guolong;JIANG Shan;YU Honglong;WANG Changdong;HUANG Xiao;LIU Qing;YANG Zhiliang;WU Fei(Geologic Party No.243,CNNC,Chifeng,Inner Mongolia 024000,China)

机构地区：[1]核工业二四三大队,内蒙古赤峰024000

出　　处：《铀矿地质》2023年第3期337-349,共13页Uranium Geology

基　　金：中国核工业地质局项目“松辽盆地通辽-大庆地区铀矿资源调查评价与勘查”(编号:202212和“内蒙古二连盆地赛音胡都-乌里雅斯太地区铀矿资源调查评价”(编号:202102-6)联合资助。

摘　　要：松辽盆地南部DL地区近年来已发现多处大、中型铀矿床,但其上白垩统划分仍不清晰,“多层状”铀矿体发育层位尚不明确,制约了铀矿勘查工作。文章以层序地层学和沉积学为理论指导依据,通过岩心、地震、测井曲线等资料综合研究,建立DL地区上白垩统层序地层格架。将DL地区上白垩统划分为1个一级层序、3个二级层序和7个三级层序,明确以青山口组一段和二段(MS6、MS5)及姚家组一段和二段(MS4、MS3)为主要含铀的4个三级层序。本次研究对主要含铀地层层序,开展沉积微相类型、沉积相展布及演化特征研究,确定了青山口组(MS5、MS6)和姚家组一段(MS4)为辫状河沉积体系,识别出河道和河漫滩2种亚相及砂质心滩、滞留沉积、洪泛平原和洪泛沼泽4种微相;姚家组二段(MS3)为曲流河沉积体系,识别出河道、堤岸和河漫滩3种亚相及边滩、天然堤、决口扇和洪泛平原4种微相;查明铀主要富集在辫状河河道的心滩、滞留沉积和曲流河相边滩位置。对含铀地层层序的精细划分及沉积微相类型的精细刻画,可为该地区铀矿勘查提供依据。In recent years,large and medium-sized uranium deposits have been discovered in DL area of the southern Songliao Basin.However the division of the Upper Creataceous is unclear and the development of"multi-layered"uranium deposits is not yet well defined,which has hindered uranium exploration work.Based on the sequence stratigraphy and sedimentology theory,a comprehensive study of core sample,seismic and logging curves was conducted to set up the sequence stratigraphic frame of the Upper Cretaceous in DL area.The Upper Cretaceous in the DL area was divided into one first-level sequence,three second-level sequences and seven tertiary sequences.The first and second Member(MS5,MS6)of the Qingshankou Formation and the first and second Member(MS3,MS4)of the Yaojia Formation(MS3,MS4)were clearly recognized as the four tertiary sequences for the main uranium-bearing layers.The Qingshankou Formation(MS5,MS6)and the Yaojia Formation(MS4)were identified as braided river sedimentary systems,and two subfacies of river channel and floodplain,and four microfacies of sandy core beach,retained sedimentary,floodplain and flood swamp were identified within the formation.The second Member of the Yaojia Formation(MS3)was identified as meandering river sedimentary system,and three subfacies of river channel,embankment and floodplain and four microfacies of side beach,natural dike,broken fan and floodplain were divided in detail.The favorable locations where uranium is mainly enriched was the heart flats,retained sediments and meandering river facies of the braided river channel.The fine division of uranium-bearing layers and the fine characterization of sedimentary microfacies types will provide a basis for uranium exploration in this area.

关 键 词：层序划分 辫状河 曲流河 沉积特征 上白垩统 DL地区 

分 类 号：P619.14[天文地球—矿床学]