滇西施甸地区寒武系-泥盆系瘤状灰岩特征及成因探讨

Discuss on Origin of the Cambrian-Devonian Nodular Limestone in Shidian Region W. Yunnan Province

施甸地区寒武系-泥盆系瘤状灰岩发育,其瘤体与基质的矿物组成、结构、构造不尽相同,可识别出不同的成因类型:上寒武统保山组中瘤状灰岩是暴露成因的,即灰泥沉积层间歇性地暴露干裂、移位磨蚀,并被后期沉积物充填胶结而成;奥陶系-泥盆系中的瘤状灰岩是沉积物沉积时期周期性海底溶解和成岩过程中差异性压实和压溶共同作用的产物。岩石中各组分含量及后期压溶作用强度的差异导致了瘤状灰岩不同的存在形式。

There is abundant distribution of odular limestone in Shidian region, the mineral component, texture, and structure of both the nodular and matrix is different, so these nodular limestone can be assorted into different types ： Nodular limestone of Cambrian Baoshan formation was formed with exposure ; Nodular limestone of Ordoviclan-Devonian was the result of periodic halmyrolysis and pressure solution and compaction in process with aliagenesis. Difference content with composition on the rock and intension of pressure solution subsequent made for three kinds of different modality.