右江盆地都安组白云岩成因及其地质意义

Genesis of Dolostone in Du’an Formation of Youjiang Basin and Its Geological Significance

以都结剖面为例,逐步开展沉积环境分析和岩石学分析方面的工作,旨在进一步提高右江盆地下石炭统都安组白云岩的研究程度.该白云岩形成于同生、准同生阶段的萨布哈模式,并在后生埋藏阶段受到埋藏白云石化作用的改造.都安组白云岩地层、下伏潮间带黏结灰岩地层及浅水潮下带颗粒-泥粒灰岩地层共同构成环潮坪型碳酸盐岩米级旋回,为晚古生代冰川作用在谢尔普霍夫期的发育提供了沉积学证据.

Taking the Dujie section as an example,the sedimentary environment analysis and petrological analysis were carried out to further improve the research level on the dolomites of the Lower Carboniferous Du’an Formation in the Youjiang Basin.The dolostone was formed in the Sabkha model of the syngenetic and peneogenetic stages,and was transformed by burial dolomitization in the epigenetic stage.The dolostone stratum of the Du’an Formation,the bonded limestone stratum in the intertidal zone and the grainstone-packstone stratum in the shallow subtidal zone constitute the tidal-flat carbonate rock meter-scale sequence,which provids sedimentological evidence for the development of the Late Paleozoic glaciation in the Serpukhovian.