Vertical and Incline Shaft Sinking at North Star Mine

- Organization:
- The American Institute of Mining, Metallurgical, and Petroleum Engineers
- Pages:
- 21
- File Size:
- 690 KB
- Publication Date:
- Jan 1, 1930
Abstract
AT THE end of the year 1914, the main North Star incline shaft had reached the 6300-ft. level, and encountered a vein dipping Southwest, or, exactly opposite to the North Star. Subsequent development failed to find the North Star vein continuing beyond this intersection, so the 6300-ft. level proved to be the bottom level of the North. Star vein, and very little ore was found below the 5300-ft. level. The new vein was called No. 1 vein. Development work carried on for the next 10 years discovered a third vein, called No. 2, branching off about 1200-ft. to the east, with a North-south strike and a west dip. No. 1 vein had about 900 ft. of backs above the 6300-ft. level before reaching the boundary line of the property, and No. 2 vein died out about 800 ft. above. During these 10 years, the money spent on development was increased from $54,000 in 1914 to $184,000 in 1924; the ore reserves steadily diminished until it was evident that the mine must close down unless by some means a large tonnage of ore could be developed quickly.
Citation
APA:
(1930) Vertical and Incline Shaft Sinking at North Star MineMLA: Vertical and Incline Shaft Sinking at North Star Mine. The American Institute of Mining, Metallurgical, and Petroleum Engineers, 1930.