Coal Measures
煤系
煤层组
煤系地层
煤系烃源岩
含煤层
含煤岩系
合煤岩系
含煤地层
煤矿
上石炭系
煤层
燕山运动
煤田
硬质高岭土
coal measures and red beds
coal measures depositional environment
Coal Measures Kaolinite
coal measures reservoir
hard kaolin (kaolinite) in coal measures strata
High-iron and high-titanium coal measures kaolin d
Inner Mongolia kaolin of coal measures
Iron-and carbon-rich kaolin in coal measures
Kaolin from Coal Measures
Kaolin of coal measures