zhè / xiē / kē / lì / zài / shuǐ / fèn / zuò / yòng / xià / zhú / jiàn / jiāo / jié / chéng / jiān / yìng / de / yán / céng

这些颗粒在水分作用下逐渐胶结成坚硬的岩层。

These particles gradually cement together into hard rock layers under the action of moisture.