Drift mining

Coal miner standing in a drift portal at Fork Mountain, TN, 1920.

Drift mine entry in West Virginia, 1908. Photo by Lewis Hine.

Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. A drift mine is an underground mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into the ore seam. Random House dictionary says the origin of the term "drift mine" is an Americanism, circa 1885-1890.

单词	Drift mining
释义	Drift mining 英语百科 Drift mining Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. A drift mine is an underground mine in which the entry or access is above water level and generally on the slope of a hill, driven horizontally into the ore seam. Random House dictionary says the origin of the term "drift mine" is an Americanism, circa 1885-1890.
随便看	sawmills的意思 Sawmill sawyer的意思 saw mill waste的意思 sawmont的意思 sawmplar的意思 sawmplere的意思 sawms的意思 saw much of的意思 saw my way clear to do的意思 saw my way clear to doing的意思 saw my way to do的意思 saw my way to doing的意思 sawn的意思 sawnap的意思 sawnape的意思 sawnce bell的意思 Sawndip的意思 sawndres的意思 sawnee的意思 sawn的意思 sawn的意思 sawney的意思 sawney的意思 sawn face的意思 sawn full的意思