摘要
承德地区滦平—承德和大杖子—新城子晚侏罗世沉积盆地带分别与丰宁—隆化逆冲带和尚义—平泉逆冲带相邻。盆地充填的土城子组在垂向上可划分出三个主要由辫状河冲积平原及辫状河三角洲沉积体系组成的盆地相。沉积物岩屑和砾石成分统计表明 ,滦平—承德盆地北缘岩屑岩性相在垂向上表现出三个基底变质岩岩屑向上增多的旋回 ,而滦平—承德盆地南缘及大杖子—新城子盆地则由碳酸盐岩和碎屑岩岩屑表现出三个向上增多的旋回。盆地沉积学特征表明 ,滦平—承德盆地南北边缘分别受控于尚义—平泉北缘和丰宁—隆化逆冲带 ,而大杖子—新城子盆地受控于尚义—平泉南缘逆冲带。如果承德断层发生了长距离逆冲推覆活动 ,其活动时间绝非土城子组同沉积期和之后 ,应该发生于髫髻山组沉积之后和土城子组沉积之前。
The Late Jurassic Luanping-Chengde and Dazhangzi-Xinchengzi basins are linked with Fengning-Longhua and Shangyi-Pingquan thrust belts, respectively. The basin-fill of the Tuchengzi Formation is vertically divided into three basin-phases, which consist of braided channel plain and braided channel delta depositional systems. The statistics of the components of the sediment lithic fragments and gravels shows that there are three vertical cycles of metamorphite lithic fragment increase upwards in the northern Luanping-Chengde Basin, and three vertical cycles of carbonate and clasolite lithic fragment increase upwards in the southern Luanping-Chengde Basin and Dazhangzi-Xinchengzi Basin. Several conclusions have been made from basin sedimentology study. The southern and northern margins of the Luanping-Chengde Basin were controlled by the northern Shangyi-Pingquan thrust faults and Fengning-Longhua thrust faults, respectively, and the Dazhangzi-Xinchengzi Basin controlled by the southern Shangyi-Pingquan thrust fault. If a long distance thrust happened along the Chengde fault, the thrust might have not occurred at the syn-depositional stage of the Tuchengzi Formation or later, but should have occurred after the Tiaojishan Formation and before the Tuchengzi Formation. The three lithic petrofacies cycles and basin phases in the basins represent three uplift and unroofing processes along the basin marginal thrust belts.
出处
《地学前缘》
EI
CAS
CSCD
2004年第3期245-254,共10页
Earth Science Frontiers
基金
国家重点基础研究发展规划项目 (G1 9990 4330 3)
教育部留学回国人员科研启动基金资助项目
关键词
承德
土城子组
盆地充填
岩屑岩性相
构造作用
Chengde
Tuchengzi Formation
basin-fill
lithic petrofacies
tectonism
