摘要
利用探地雷达勘探技术对鄂尔多斯盆地曲流河三角洲前缘及三角洲平原分支河道露头砂岩体的分布特征进行实测并描述。研究区岩性主要为泥岩、泥岩与粉-细砂岩互层,夹薄层凝灰岩,且多数地段表层覆盖1~5 m厚的黄土。对雷达剖面进行一系列数据处理并定量给出7个主要砂岩体的厚度依次为54 m、83 m、54 m、38 m、104 m、160 m、191 m;高度依次为6 m、7 m、5 m、8 m、6 m、10m、9 m,等参数;砂岩体长厚比值依次为9、11.8、10.8、4.8、17、16、21.2。河道砂岩主体宽与高的比值总体上〉15,整体呈现砂岩泥岩复合式沉积构造。砂岩体多呈现孤立状顶部平缓底部突起透镜体形态,河道纵向多期沉积明显且有砂岩体横向迁移现象,砂岩体在探地雷达剖面的反射特征与观测结果一致。
The distribution characteristics of outcrop sandbodies of meandering river delta front and delta plain distributary channels in the Ordos Basin were observed and described by utilizing the GPR exploration technique.The lithology of the studied area is mainly mudstone,interbeded mudstone and siltstone and fine-grained sandstone,intercalated with thin layered tuff,mainly coverd by loess in 1 ~ 5 m thickness in the surface of the area. A series of data processing and quantitative analysis of 7 main sand bodies,such as thickness,height,are given. The lateral scales of sandstone body are 54 m,83 m,54 m,38 m,104 m,160 m,191 m and the vertical scale of sand body are 6 m,7 m,5 m,8 m,6 m,10 m,9 m. The ratio of the length and thickness of sandstone is 9,11. 8,10. 8,4. 8,17,16,21. 2,respectively. The ratio of the width and the overall height of the river sandstone body is higher than 15,and the overall presentation of the sandstone and mudstone is composite sedimentary structures.The sandstone body presents isolated lens in shape with gentle top and protuberant bottom. Multi-staged period deposition is obvious in longitudinal river sandstone body and there are lateral migration. The reflection characteristicsof the GPR profiles agree well to the results.
出处
《世界地质》
CAS
2016年第1期223-234,共12页
World Geology
基金
高等学校博士学科点专项科研基金(博导类)(20130061110061)资助
关键词
探地雷达
砂岩体
沉积
曲流河三角洲
延长组
ground penetrating radar
sandstone body
deposition
meandering stream delta
Yanchang Formation
