煤层和含煤地层的基本形态取决于沉积矿床的原始沉积。煤层近似于一种板状结构。但将煤层描述成厚薄均匀的板体则是不正确的。在沉积过程中,如果植物体横向堆积不均匀和混乱,则将会造成煤层不稳定隆起、交替和变薄等等。而这些煤层形态的不规则性又由于煤田内的构造运动变得更加复杂。但在这里,我们仅就水力采煤对煤层的三种基本形态进行描述。 The basic form of coal and coal-bearing strata depends on the original deposition of the deposit. The coal seam is similar to a plate-like structure. However, it is not correct to describe the coal seam as a plate with a uniform thickness. In the deposition process, if the plant horizontal stacking uneven and chaos, it will cause the unstable instability of the coal seam, alternating and thinning and so on. The irregular shape of these coal layers is further complicated by the tectonic movement in the coalfield. But here, we only describe the three basic forms of coal seam by hydraulic coal mining.