The test results show that the Yuan Baoshan red soil contains Illite Smectite (I S) and has a pore fissure structure, and it is characterized by low compressibility, high strength while air dried and heavily disintegration while wetted.

Coefficient of variation and its application in orderliness judgment of illite-montmorillonite mixed-layer mineral

The quantitative study is conduted on the XRD data of clay minerals in 15 mudstone samples from the Well Ancan 1 in Hefei Basin,and the testing results of illite crystallinity and illite/smectite interlaying reveal the stratigraphical diagenesis degree and thermal evolution degree of the strata met by the deep well drilling.

Illite can be transformed into montmorillonite under certain conditions and be transformed firstly into I/S mixed-layer minerals which will affect the minerals properties and process properties of illite.

Based on the sectioned quantitative study of XRD data of clay minerals in argillites from two wells in Zhujiangkou Basin,it is proved that the increase of the ratio of illite and smectite layer contents in illite smectite mixed layer clay(I/S)is related mainly to the dissolution of potassium feldspar.