中扬子二叠系白云石化模式

中扬子二叠系发育局部白云石化和层状白云石化两种式,局部白云石化呈树枝状、斑块状见于不同层位之中,形成白云石化灰岩;层状白云石化分布稳定,形成层状白云岩。通过白云石化产状、X射线粉晶衍射特征、微量元素及稳定同位素特征的研究表明:局部白云石化为成岩期的调整白云石化模式,层状白云石化为同生——准同生期混合水白云石化模式。

PERMIAN DOLOMITIZATION MODEL OF THE MIDDLE YANGTZE METAPLATFORM

The middle Yangtze Metaplatform developed two forms of dolomitization in Permian, the plot dolomitization and the layer dolomitization. The plot dolomitization appears in plot and tree-like shape in different layers. The rock becomes dolomitized limestone in which the plot dolomitization occurs. The layer dolomitization appears in stable layers and forms layer dolotone. Two conclusions, i. e. the plot dolomization is the adjustment model in the diagentic stage and the layer dolomitization is the mixed water model in the syngenetic stage or metasyngenetic stage, are reached after emphatically dissecting dolomitization characteristics of occurrence, X-ray powder diffraction analysis, trace element and stable isotopic analyses.