Results: 1 - 2 of 2
Dec 16, 1972
Open File Report
… ranging from 0 (i.e. at the surface) to 10,000 feet. Although … by conventional underground and surface mining techniques. This constitutes …
Dec 31, 1975
Bulletin
… short residence time below the surface. Response to changes in … disturbed. Logging and strip mining are not recommended in these …