10               淤泥          10~14 有机土类         11               淤泥质土         12               泥炭         13               泥炭质土         14               有机质土

        20               黄土          20~28 特殊土类         21               黄土状粉质黏土         22               黄土状粉土         23               红黏土         24               盐渍土         25               膨胀土         26               污染土         27               多年冻土         28               古土壤

        30               黏土          30~36 粘性土类         31               重亚黏         32               中亚黏         33               轻亚黏         34               亚黏         35               重粉质黏土         36               粉质黏土

        37               黏质粉土      37~39 粉土类         38               粉土         39               砂质粉土

        40               粉砂          40~44 砂土类         41               细砂         42               中砂         43               粗砂         44               砾砂

        50               圆砾          50~55 砾石类         51               角砾         52               卵石         53               碎石         54               漂石         55               块石

        60               花岗岩        60~87 岩石类         61               闪长岩         62               辉长岩         63               玢岩         64               流纹岩         65               安山岩         66               粗面岩         67               玄武岩         68               凝灰岩         69               火山角砾岩         70               砾岩         71               角砾岩         72               砂岩         73               泥岩         74               页岩         75               泥灰岩         76               石灰岩         77               白云岩         78               煤层         79               片麻岩         80               片岩         81               板岩         82               大理岩         83               石英岩         84               千枚岩         85               混合岩         86               糜棱岩         87               泥质粉砂岩         99               溶洞          溶洞99，固定编码

岩性编码可以是一个，也可以是两种岩性混合，比如：粗砂混卵石，编码是：4352