贵州南部都匀剖面奥陶系红花园组地层沉积微相与层序特征

Stratigraphic Sedimentary Microfacies and Sequence Characteristics of the Ordovician Honghuayuan Formation on Duyun Profile of Southern Guizhou

本文在野外地质调查和岩石薄片镜下观察的基础上,对贵州南部都匀剖面的古生界奥陶系红花园组的地层沉积微相识别和层序地层特征进行了系统研究。研究认为,都匀剖面的红花园组地层可划分为13个沉积微相,含海侵体系域和高位体系域,划归为三级Ⅱ型层序。红花园组下段以白云岩、白云质灰岩为主,反映了高盐、强烈蒸发的潮坪沉积环境;中、上段主要为生屑岩屑灰岩、鲕粒灰岩和岩溶角砾岩,反映了动荡水体中的高能浅滩沉积环境。由潮坪相向浅滩相的变化则指示了红花园组属于一个缓慢的次级海侵时期。

We had studied on the stratigraphic sedimentary microfacies and sequence characteristics of the Paleozoic ordovician Honghuayuan formation at Duyun profile of southern Guizhou Province based on field survey and microscopic identification for rock slices. 13 microfacies and the 3rd type-Ⅱ sedimentary sequence with transgressive system and high system tract were recognized in Duyun profile. Dolomite dominating the lower Honghuayuan formation indicated hypersaline and intensive evaporation tidal flat sedimentary environment. Bioclastic lithic granular limestone, oolitic limestone and karst breccia of the middle-upper Honghuayuan formation indicated high energy shoal faces in turbulent water environment. Sedimentary faces changes from tidal flat to shoal suggested that Honghuayuan formation belonged to a slow secondary transgression period.