摘要
承德地区土城子组的沉积地层,主要保存在两个地区,一处为承德向斜,另一处为古北口断层的南部紧邻断层地区,即分别命名的承德盆地和古北口盆地内。根据其沉积特征,可分两个阶段。土城子组沉积早期阶段,盆地充填自下而上表现为冲积扇、砾质辫状河到曲流河的沉积过程。晚期阶段,承德盆地南部以及古北口盆地内近断层处,皆表现为冲积扇沉积,沉积物较早期地层有明显不同,碳酸盐岩颗粒占据主要成分,并沿剖面向上增加;承德盆地南半部分和古北口盆地内古流向分别为自南向北和自北向南。区域构造和土城子组沉积特征表明,在土城子组沉积晚期阶段,该地区构造环境发生了由伸展到挤压的转变,同时可能使盆地发生了正反转。
The sedimentation of Tuchengzi Formation was mainly preserved in Chengde syncline and in the south part of Gubeikou fault in Chengde area, namely Chengde basin and Gubeikou basin, respectively. Based on its sedimentary characteristics, two stages were divided for its sedimentation. In the early stage, the sedimentary facies are mainly alluvial fan facies, gravel - bed braided - meandering river facies extending from base to top in the vertical direction. In the later stage, the sedimentation of alluvial fan facies prevailed in the south of Chengde basin and the north of Gubeikou basin near the fault, the clastic sediments were different from those of the early stage, and the percentage of carbonate clasts was higher than those of any others in the the clastic sediments and shows an increase in sections in an upward direction; the paleocurrents in the south of Chengde basin and Gubeikou basin were directed to the north and south, respectively. The characteristics of regional structures and the sedimentation of Tuchengzi Formation reflect that the structural environment underwent a conversion from extension to contraction, and a positive inversion may have occurred in the basin.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2005年第4期465-474,共10页
Geotectonica et Metallogenia
基金
中国科学院知识创新工程资助项目(KZCX1-07-03).
关键词
土城子组
承德向斜
古北口断层
古流向及物源
承德地区
燕山造山带
Tuchengzi Formation
Chengde syncline
Gubeikou fault
paleocurrent and provenance
Chengde area
Yanshan orogenic belts
