湖南桃江半边山前寒武纪内潮汐沉积及其共生沉积特征

Internal-tide Deposits and Paragenetic Sedimentary Characteristics of Precambrian in Banbianshan of Taojiang Area of Hunan Province

湖南桃江半边山前寒武纪马底驿组为一深水重力流沉积、深水牵引流沉积与深水原地沉积共生组合。原地沉积为水平层理发育的暗色泥板岩。重力流沉积为暗灰、灰色的厚层滑塌沉积、碎屑流沉积和薄中层浊流沉积组合。深水牵引流沉积为内潮汐沉积类型,岩性为细砂岩、粉砂岩,以发育透镜状、波状、脉状层理、双向交错层理、波痕等沉积构造为特征。深水原地沉积与异地沉积在剖面上组成了复杂的复理石韵律。研究表明研究区内潮汐沉积属于水道型内潮汐沉积。

Precambrian Madiyi Formation in Banbianshan, Taojiang of Hunan Province is consisted of deep-water gravity flow deposits, deep-water traction current deposits and deep-water in situ deposits. In situ deposits are dark shale with horizontal bedding. Gravity flow deposits are consisted of thick dark-gray and gray slump deposits, debris-flow deposits and thin-medium bedded turbidite deposits. The dark-gray traction current deposits belong to internal-tide deposits, it develops sandstones and siltsands, and charactered with lenticular, wave, flaser bedding, bimodal cross-bedding and ripple mark. The deep-water in situ deposits and deep-water allogene deposits develop flysch rhythmic sequences. The internal-tide deposits in this area belong to channel internal-tide deposits.