摘要
据冀中坳陷南部晋县凹陷钻井岩心砂岩碎屑组分、重矿物以及部分常量元素的序列变化分析 ,该区古近纪地壳曾发生强烈的断块翘倾运动 ,主要物源类型变化反映裂谷盆地边缘的断块构造背景。砂岩类型从孔二段岩屑砂岩到孔一段至沙二段岩屑长石砂岩、岩屑长石石英砂岩再到沙一—东营组岩屑砂岩 ,为一旋回过程。在垂向上 ,石英组分向上递增 ;长石组分呈低高低变化 ;而碳酸盐岩屑组分则显示上下高、中部低的特点 ,与正常的地层序列不相匹配。结合盆缘构造演化研究认为 ,在孔二段大量出现的高碳酸盐岩屑与断块翘倾并与可能的燕山期逆冲断块的侵蚀有关。
According to research on the variation of detrital composition, heavy minerals and major elements in the Lower Tertiary sandstone from southern Jizhong basin, together with local fault block tilting movement, this paper presents that the primary provenance type reflected fault block tectonic setting at the margin of the rift basin. The sandstone type experienced a cyclic change from lithic sandstone of the 2nd member of the Kongdian Formation, lithic arkose and lithic arkosic quartz sandstone of the 1st member of the Kongdian Formation and the 4th-2nd members of the Shahejie Formation again to lithic sandstone of the 1st member of the Shahejie Formation and the Dongying Formation. In the stratigraphic cross-section, the quartz composition increased upwards, the feldspar composition showed a lower-high-lower variation trend and the lithiclast showing high-lower-high. This condition is contradicted with the natural stratigraphic sequence. In virtue of tectonic evolution at the basin margin, the high lithiclast at the 2nd member of the Kongdian Formation is associated with fault block tilting movement and strong erosion action of nappe sheet possibly was formed in the Yanshanian movement.
出处
《矿物学报》
CAS
CSCD
北大核心
2003年第2期136-142,共7页
Acta Mineralogica Sinica
基金
国家重点基础研究发展规划项目 (G19990 43 2 0 9)
日本科技厅科技交流项目 ( 97- FT0-1-5 )
