碳酸盐岩中自生碳酸盐矿物主要为文石、高镁方解石，少量白云石、铁白云石和菱铁矿。镁方解石质生物富积带（60-400m）；
X-ray studies show that carbonate minerals are aragonite , high-Mg calcite , and lesser dolomite , ankerite and siderite . 2 . Rich magnesium calcite organism accumulation zone , whose depth distribution ranges from 60-400m ;
高镁方解石