On the basis of study on the petrographic characteristics of coal 2 -2 in Shenmu Coalfield,three types of peat swamp are recognized,i.e.

• 在研究神木煤田2-2煤层煤岩特征的基础上，划分了三种泥炭沼泽类型，即开阔水体草本沼泽、陆地森林沼泽和潮湿森林沼泽。