摘要
为系统厘定并全面总结准噶尔盆地东部卡姆斯特地区侏罗系各时期的沉积演化规律及砂体空间展布特征与铀成矿之间的关系,文章通过大量钻孔岩心观察、钻孔测井数据并综合盆地的构造-沉积响应,对卡姆斯特地区侏罗系各时期的岩性-岩相特征、沉积建造特征、沉积相类型、砂体形态及平面展布特征和沉积演化规律进行了详细研究,得出:卡姆斯特地区侏罗系八道湾沉积时期发育一套辫状河-辫状河三角洲含煤粗碎屑沉积;三工河沉积时期处于湖泊扩张期,发育细粒的湖相沉积;西山窑沉积时期为一套湖退含煤碎屑沉积;头屯河沉积时期发育一套大型湖退岩性-岩相序列,是中侏罗世区域性构造活动隆升导致湖盆萎缩的沉积响应。卡姆斯特地区侏罗系自下而上共发育三套对砂岩型铀成矿有利的沉积建造,其中头屯河组下段的原生灰色粗碎屑建造是首要优势建造类型,八道湾组上段底部的灰色含煤粗碎屑建造和西山窑组暗色煤岩建造作为具勘探潜力的沉积建造类型次之。卡姆斯特地区侏罗系沉积演化决定了垂向上的岩性-岩相组合特征,从而控制了砂岩型铀成矿的发育层位和砂体类型,在空间上连续的湖退-湖进形成一系列低位体系域和高位体系域沉积产物,易发育大型骨架砂体,形成了头屯河组、八道湾组、西山窑组等一系列具备发育铀矿化岩性-岩相条件和良好空间配置的优选目标层位。
In this paper,the lithology-lithofacies characteristics,sedimentary characteristics,sand body morphology and plane distribution characteristics and sedimentary evolution of Jurassic in different epoch were researched in detail by the observation of a large number of borehole core,statistics on drilling and logging data and the analysis of the tectonicsedimentary response of the basin.It was concluded that a set of coal-bearing coarse clastic sediments of braided riverbraided river delta were developed in the sedimentary stage of Badaowan Formation of Jurassic in Kamusite.Sangonghe Formation was formed in the lake expansion epoch and developed fine-grained lacustrine deposits;Xishanyao Formation was a set of lacustrine coal-bearing clastic deposits;Toutunhe Formation was developed with a set of large lacustrine regressive lithologic-facies sequence,which was the sedimentary response to the lake-basin atrophy caused by regional tectonic uplift in Middle Jurassic.Three sedimentary formations favorable for sandstone-type uranium mineralization were developed in Jurassic strata from bottom to top,namely,the grey coal-bearing sedimentary formation at the bottom of the upper part of Badaowan Formation,the dark coal-rock formation of Xishanyao Formation and the primary grey sedimentary formation in the lower part of Toutunhe Formation.The sedimentary evolution of Jurassic determined the vertical lithologic-lithofacies combination characteristics and controlled the development horizon and sand body type for sandstone-type uranium mineralization.A series of sedimentary products of low stand system tract and high stand system tract were formed in the continuous lake regression-lake transgression in space,which is easy to form large skeleton sand bodies and resulting the formation of target horizons with good lithologic-lithofacies conditions and spatial configuration for uranium mineralization in Toutunhe Formation and Baodaowan Formation and Xishanyao Formation.
作者
冀华丽
何中波
钟军
郭强
朱斌
吴玉
东前
JI Huali;HE Zhongbo;ZHONG Jun;GUO Qiang;ZHU Bin;WU Yu;DONG Qian(National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing,Beijing 100029,China;Beijing Research Institute of Uranium Geology,Beijing 100029,China;CNNC Key Laboratory of Uranium Resources Exploration and Evaluation Techniques,Beijing 100029,China)
出处
《铀矿地质》
CAS
CSCD
2024年第6期1019-1041,共23页
Uranium Geology
基金
新疆维吾尔自治区重大科技专项“新疆准噶尔铀成矿带成矿规律与勘查增储研究”
铀资源探采与核遥感全国重点实验室基金项目“砂岩型铀矿有利成矿砂体识别定位研究”
中核集团青年英才“菁英”项目(编号:地QNYC2201)联合资助。
关键词
侏罗系
沉积特征
沉积建造
砂岩型铀矿化
卡姆斯特
Jurassic
sedimentary characteristics
sedimentary construction
sandstone-type uranium mineralization
Kamusite
