关于底砾层的成因问题，有多种观点。
There are many viewpoints about the genesis of the "bottom gravel".
第四纪底砾层直接覆盖在谢桥煤矿煤系地层之上，其隔水性能影响到防水煤柱的合理留设。
The main target coal seam of Xieqiao Mine is directly covered with the Quaternary bottom gravels, whose impermeability affects the reasonable retainment of waterproof pillar.
第四纪底砾层直接覆盖在谢桥煤矿煤系地层之上，其隔水性能影响到防水煤柱的合理留设。
The main target coal seam of Xieqiao Mine is directly covered with the Quaternary bottom gravels, whose impermeability affects the reasonable retainment of waterproof pillar.
应用推荐