摘要
湖南冷家溪群主要分布在湘东北地区,大药菇组为其顶部层位,1:20万蒲溪幅区域地质调查时建组,现在沿用并重新定义为整合于小木坪组之上、不整合于板溪群"宝林冲组"或横路冲组之下的一套浅变质含砾杂砂岩、岩屑杂砂岩与砂质板岩、板岩构成的多个层序并夹砾岩的岩石组合体,厚度>730.2m。通过剖面研究,可以划分出三个由粗到细的岩性旋回;砂岩主要属杂砂岩类;砾岩中砾石以内源成份为主。依据岩石结构序列,结合粒度参数的统计分析,认为大药菇组属于沉积盆地进入萎缩期、构造活动增强的沉积响应,反映的水动力条件是阵发性的快速流动机制,属于海底扇浊流体系沉积。
Lengjiaxi Group of Hunan province is mainly distributed in northeast Hunan, the upper part of which is composing of Dayaogu Formation, which is established by regional geological surveying of the scale of 1：200 000 Puxi map, and redefined as the one which is conformity above the Hengluchong Formation and unconformity under the ＂ Baolinchong Formation＂ or the Xiaomuping Formation, and consisted of lightly metamorphic conglomeratic graywackes, lithi graywackes and states interbeded with conglomerates, exceeded 730.2 meter in thickness. The Dayaogu Formation can be divided into three sedimentary cycles from coarsely to fine in grain size, and the gravel is mainly from the interior source. According to the rock structure and the grain size parameter statistical analysis, we found that the Dayaogu Formation is deposited in paroxysmal rapid flow hydrodynamic condition in the stage when the depositional basin getting into shrink age and the structure movement is enhanced, and is belonged to turbidity deposition in submarine fan system.
出处
《华南地质与矿产》
CAS
2009年第4期54-58,共5页
Geology and Mineral Resources of South China
关键词
大药菇组
冷家溪群
湖南
Dayaogu Formation
Lengjiaxi Group
Hunan province
