During the initial excavation, the tender coal seam workings in deepseam in Nantun Colliery takes on slocking of roof, with breaking-out in bulk coal and surrounding rock failure.
南屯煤矿深部松软煤层巷道，在掘进过程中顶板破碎，伴有大量顶煤冒落且围岩破坏严重。
2
The seam averages more than 50 meters wide - one of the world's thickest - and 250 meters deep, though portions of it go down at least 600 meters.
平均煤层宽度大于50米——世界上最厚之一——并且有250米深，尽管其中部分可能至少在600米之下。
3
Others aspire downwards deep in the St. Regis canoe Area, floating in a seam of light, a silent wake trailing behind their canoe.