塔中地区中晚奥陶世灰泥丘是在古老碳酸盐岩台地逐渐沉没过程中生长发育的。横向上，它向台地高部位层层爬坡，纵向上，为多旋回叠丘。建造灰泥砂丘的生物主要是菌藻类—奥特藻及其相近的属，尚有珊瑚、苔藓虫、层孔虫、海绵等。其岩石类型主要是泥晶凝块格架岩、泥晶凝块障积格架岩、泥晶藻凝块粘结岩。其沉积相可分为丘中心、丘前和丘间三个相带。灰泥丘的演化受控于海进速率同灰泥丘的增长速率及海水深度与浊度。 Middle-Late Ordovician stucco mounds in the Tazhong area grew and developed during the gradual submergence of the ancient carbonate platform. In the horizontal direction, it climbs up the layers of the upper part of the platform, and in the longitudinal direction, it is a multi-turnup fold. Creatures of stucco sand mounds are mainly bacteria and algae - algae algae and their similar genus, there are corals, bryozoans, stomatal, sponges and so on. The rock types are mainly mudstone clinker bedrock, mudstone clinker bedrock, mudstone algae clinker rock. The sedimentary facies can be divided into mound center, mound and mound three facies. The evolution of stucco mounds is controlled by the rate of sea-going growth and the growth rate of mud mounds as well as seawater depth and turbidity.