塔里木盆地西南缘齐姆根—桑株河地区石炭—二叠系沉积特征及沉积相

SEDIMENTARY FACIES AND CHARACTERISTICS OF CARBONIFEROUS AND PERMIAN OF SOUTHWEST MARGIN OF QIMUGENSANGZHUHE DISTRICT IN TARIM BASIN

早石炭世海侵范围较小,莫莫克以东为古岛,以西为向北西倾斜的水下隆起,为局限台地-开阔台地相清水碳酸盐岩和混积陆棚相沉积;晚石炭世早期海侵范围扩大,铁克力克古岛沦为水下隆起,莫莫克以西为较厚的混积陆棚相和滨岸相砂岩沉积,以东为局限台地-开阔台地相清水碳酸盐岩沉积;晚石炭世中期为稳定的海侵期,形成潮坪-局限台地-开阔海台地相清水碳酸盐岩沉积;晚石炭世晚期—早二叠世早期为规模最大的海侵期,也是塔西南碳酸盐岩台地发育的鼎盛时期,其重要标志是形成了台地边缘礁滩相带,高能浅滩相最为发育.莫莫克以西地区下二叠统棋盘组为海陆交互相沉积、上二叠统达里约尔组为湖泊-河流相沉积,莫莫克以东地区下二叠统普司格组为河流-湖泊-扇三角洲相沉积、上二叠统杜瓦组为冲积扇-扇三角洲相沉积.

The transgression range of early Carboniferous is relatively small. To the east of Momoke is anciet islands, to the west is a north-west dipped underwater uplift. They are fresh-water Carbonate reservoirs of limitedopen palteform facies and mixed depositions of continental shelf facies. The transgression range of late carboniferous is relatively large, during which Tiekelike ancient island became a underwater uplift. To the west of Momoke are thick sandstones of mixed continental shelf and Littoral facies. To the east is fresh-water carbonate sediments of limited-open platform facies. Fresh-water carbonate sediments of tidal flat-limited-open platform facies were formed during the middle stage of late Carboniferous which was a stable transgression period. The late stage of late Carboniferous to the early stage of early Permian was the largest-scale transgression period and the prosperous period of carbonate platform development in southwest Tarim basin, of which the significant symbol was the formation of reef beach facies at the edge of the platform with the high-engery shoal facies of most developed. Qipan formation of Lower Permain to the west of Momoke is sediments of interbedded marine-continent facies, Daliyuer formation of lake-fluvial facies. Pusige formation of lower Permian to the east of Momoke is sediments of fluvial-lake-fan-delta facies, Duwa formation of upper Permian of alluvial-fan-delta facies.