煤岩类型 meaning in English

coal type
ingredient
lithotype
zone type

Classification of macrolithotype for bituminous coal
烟煤的宏观煤岩类型分类
Determination of microlithotype composition
显微煤岩类型测定方法
Classification of microlithotype
显微煤岩类型分类
The relationship between microlithotype and the distribution of cleat in coal bed is discussed through a case from hedong coalfield , combining microstratigraphy and statistics methods
摘要综合利用显微地层学和统计学方法，以河东煤田中北部8煤层为例，研究了煤层显微煤岩类型与煤层裂隙分布的关系。