摘要
通过对北祁连阴凹槽石炭系羊虎沟组砾岩层分布、剖面特征以及砾石组合特征分析,结合晚石炭世北祁连大地沉积环境及周围古陆地区的岩性特征,阐述了该砾岩层的性质、成因、物源和搬运方式,探讨了砾岩的沉积环境、水动力条件、古气候及构造特征等。运用统计学方法研究表明,阴凹槽羊虎沟组砾岩是一套典型的滨浅海底砾岩,其中所含的3套砾岩在成因、物源、沉积环境及搬运方式都具有较好的一致性。砾岩的主要物源为阿拉善地块西缘,其次为柴达木古陆。砾岩以中距离搬运为主。阴凹槽羊虎沟组砾岩具有多旋回、多期次,指示了一个以海进—海退为主不断重复的沉积过程,从整体上反映了干冷到相对潮湿的气候环境。
Based on the analysis of gravel fabric characteristics of the Carboniferous Yanghugou Formation and north Qilian sedimentary environment and adjacent old land-mountains,origins,sources,hydrodynamic conditions,climate environment and geomorphy and tectonics of Yinwacao are illustrated.Yanghugou Formation is composed of marine basal conglomerate during Late Carboniferous,of which three conglomerate layers show better consistency in origins,sources,transport,and sedimentary environment.The conglomerate layers of Yanghugou Formation are multi-periods,multi-sources,and unstable shallow marine sediment,indicating a continuous sedimentation of transgression and regression,and an environment from dry-cold to warm-humid.The conglomerate was derived from the most west margin of Alashan massif,next to Qaidam archicontinent.The conglomerates was transported mainly for a middle-distance.
出处
《桂林理工大学学报》
CAS
北大核心
2012年第4期475-481,共7页
Journal of Guilin University of Technology
基金
中国地质调查局上日木策尔等5幅1:5万区域地质调查项目(1212011121188)
关键词
砾岩层
羊虎沟组
阴凹槽
晚石炭世
滨浅海
Yanghugou Formation
conglomerate layer
Late Carboniferous epoch
coastal-shallow sea
Yinwacao
north Qilian
