摘要
通过砂岩碎屑组分统计,对直罗组砂岩碎屑组分组成特征、源岩类型、源区构造环境进行了分析,结合直罗组典型露头实测古水流数据,综合研究了直罗组沉积物源。结果表明:①直罗组砂岩结构成熟度和成分成熟度均较低,具有近源沉积特点;②源岩为与弧有关的花岗质岩石,也有部分流纹岩、安山岩、粗安岩等火山岩和绢云板岩、石英岩、浅粒岩、糜棱岩等变质岩;与基于Dickinson砂岩碎屑模型判别指示的物源区构造环境(主体为切割岛弧,基底隆起次之)相吻合;③直罗组典型露头古水流优势方向为144°,表明古流向以南南东为主,即物源主要来自盆地北北西方向。综合区域地质背景,晚古生代阿拉善右旗陆缘岩浆弧是主要物源区,与之临近的龙首山基底杂岩带也有部分贡献。
Statistics of detrital composition of sandstone from the Zhiluo Formation indicates that its texture maturity and composition maturity are low,the protolith is granitic rock related to island arc and metamorphic rock such as sericite slate,quartzite,granulite and mylonite which coincides with provenance tectonic environment indicated by Dickinson sandstone detritus model,and dominant direction of palaeocurrent in typical outcrop of the Zhiluo Formation is 144°.In combination with regional geological background,the main provenance should be the Late Paleozoic epicontinental magmatic arc in Alxa Youqi,secondly,Longshoushan basement complex belt.
作者
游水生
李振江
李有波
余旭辉
邓浩然
YOU Shui-sheng;LI Zhen-jiang;LI You-bo;YU Xu-hui;DENG Hao-ran(Regional Geological Surveying Team,BGEEMRSP,Chengdu 610213;Sichuan Institute of Geological Survey,Chengdu 610081)
出处
《四川地质学报》
2021年第S01期34-38,共5页
Acta Geologica Sichuan
基金
宁夏灵武国家地质公园恐龙化石赋存地层研究和恐龙园区遗迹保护环境评价项目资助。
关键词
直罗组
砂岩碎屑组分
物源区分析
磁窑堡
Zhiluo Formation
detrital composition of sandstone
provenance
Ciyaopu
