Based on the fact that there is serious quality differentiation between upper sandstone and lower sandstone, which is part of Donghetang Formation in Qunkuqiake structure zone, Tarim basin, the differentiation is not the result of the sedimentary diversity, but rather the difference of diagenetic alterations, the detailed microscopical study and mineral composition analysis were made. The results show that significant interval diversity of quartz cementation is the leading factor for the heterogeneity. In the lower sandstone, quartz cementation is restrained by the illite-coating, which results in good preservation of primary pore. Ubiquitous quartz is filled in most primary pore in the upper sandstone, which becomes kind of brittle. Hence, as the accompanying effect of the diagenetic diversity between the upper sandstone and the lower sandstone, crack (fracture) is preferred to develop in the upper sandstone in the same strain (pressure) condition.%基于塔里木盆地群苦恰克构造带内泥盆系东河塘组的上、下两段砂岩储层物性表现出强烈的层间差异性特征(下段砂岩储集物性明显优于上段砂岩的储集物的物性),而这种差异性并非由前期沉积水动力因素所导致,而是由后期储层内成岩改造的差异所引发,对样品进行详细的显微观测和矿物成分研究.研究结果表明:发育于埋藏成岩期石英胶结效应的层间差异造就了上述储集物性的层间差异性；下段砂岩内由于伊利石矿物以包膜的形式包裹于石英颗粒表面,抑制了石英胶结,使得原生孔隙较好地保存；而上段砂岩内强烈的石英胶结使得原生孔隙消失;其岩石物理性质呈现出刚性特征,作为东河塘组上下两段砂岩成岩改造差异的连带效应,在同等外部构造应变环境下,上段砂岩内的裂隙产出现象更加频繁.
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