摘要
运用层序地层学理论和方法对特提斯喜马拉雅东段南带聂拉木亚来剖面下石炭统纳兴组中下部沉积层序进行了研究，首次识别划分出三个Ⅱ型、三个含深切谷充填的Ⅰ型层序，对各层序特点进行了总结，重点介绍了深切谷特征，还讨论了沉积层序的时代格架、区域性和全球性对比。
Six sequences named Ⅳ1～Ⅳ4,Ch1,Ch2 with an average duration of 1.0～2.0 Ma can be recognized in the mid lower Naxing Formation of the Lower Carboniferous at Yalai,Nyalam,south Tibet,In which three sequences with type Ⅱ basal boundary surface and three with type Ⅰcould be divided by the system tract,texture and the relationship of sequence, and all of them are of slow transgression to fast regression.The identification of the incised valleies in the sequences Ⅳ4,Ch1,Ch2 is determined by (1) the shelf shale facies surrounding channel,(2) the sharp contact of boundary surface,(3)the up deepening tendency:channel bottom lag conglomerate → feldspathic quartz sandstone → shore quartz arenite → shelf shale,(4)the incised “U” shape in outcrop.And these sequences can be correlated with the mesothems in NW Europe, the T R Cycles in Russian Platform and in Mississippi Valley at the same period.Of them,the type Ⅰ sequences with incised valley fills are, to great extent related to the global regression event or the early Visean glaciationⅡin Brazil in Gondwanaland.
出处
《沉积学报》
CAS
CSCD
北大核心
1997年第1期1-6,共6页
Acta Sedimentologica Sinica
基金
国家青年科学基金
关键词
沉积层序
沉积
早石炭世
纳兴组
深切谷
glacial sea level regression event depositional sequence incised valley naxing formation nyalam south tibet
