Underground Mine Development Research Articles

Interaction of underground mining and surface development in a central city environment : Stacey, T R In: Rock Engineering and Excavation in an Urban Environment (papers to the conference, Hong Kong, 24–27 February, 1986)P397–404. Publ London: IMM, 1986

Interaction of underground mining and surface development in a central city environment : Stacey, T R In: Rock Engineering and Excavation in an Urban Environment (papers to the conference, Hong Kong, 24–27 February, 1986)P397–404. Publ London: IMM, 1986

Interaction of underground mining and surface development in a central city environment : Stacey, T R In: Rock Engineering and Excavation in an Urban Environment (papers to the conference, Hong Kong, 24–27 February, 1986)P397–404. Publ London: IMM, 1986

Interaction of underground mining and surface development in a central city environment : Stacey, T R In: Rock Engineering and Excavation in an Urban Environment (papers to the conference, Hong Kong, 24–27 February, 1986)P397–404. Publ London: IMM, 1986

Interaction of underground mining and surface development in a central city environment : Stacey, T R Trans Inst Min Metall (Sect A Min Ind)V95, Oct 1986, PA176–A180

Interaction of underground mining and surface development in a central city environment : Stacey, T R Trans Inst Min Metall (Sect A Min Ind)V95, Oct 1986, PA176–A180

Developments in Coal in 1986

In 1986, according to data from state agencies, United States mines in 26 states produced 897.9 million (short) tons of coal, a slight decrease of 0.2% from the revised 900 million tons produced in 1985. Of this coal, the Eastern Coal province produced 48.5%, the Northern Great Plains, Rocky Mountain, and Pacific Coast provinces and Alaska produced 29.2%, the Interior Coal province produced 16.7%, and the Gulf Coal province produced 5.6%. In rank, 0.4% was anthracite, 66.2% was bituminous, 24.9% was subbituminous, and 8.5% was lignite. Operators of 2,465 coal mines in Kentucky led the nation by producing 165.6 million tons of coal. Wyoming ranked second with 135.7 million tons, West Virginia was third with 130.8 million tons, Pennsylvania was fourth with 73.2 million tons, Illinois was fifth with 62.6 million tons, Texas was sixth with 48.5 million tons, Virginia was seventh with 41.8 million tons, Ohio was eighth with 34.7 million tons, Montana was ninth with 33.7 million tons, and Indiana was tenth with 31.9 million tons. A 3.6% decrease in Wyoming's coal production was the first decrease in 18 years. Development of the nation's first underground hydraulic coal mine progressed in Colorado. Surface mines produced 59% of United States coal production in 1986.

Industrial bright beam lamp

Mine development along a 15-mile (24 km) section of the Warfield Fault in Mingo County, West Virginia has broadened the geological understanding of the fault and its related structures. The fault has been exposed in two new road cuts, one in the northeast-trending segment at Neely Branch and one in the eastern east-trending segment at the head of Marrowbone Creek. Both exposures show a well-defined normal fault with a 45° to 55° N dip, juxtaposing sandstone/shale packages from the roof and the floor of the Coalburg seam. The fault is associated with a thin gouge zone, some drag folding, and parallel jointing. Its trace tends to run parallel to the crest of the adjacent Warfield Anticline. Based on underground mine development and detailed core drilling, the vertical offset along the fault plane ranges from a maximum of 240 ft (73 m) in the central part of the area near the structural bend to less than 100 ft (30 m) in western and eastern directions. The fault is located along the relatively steeply dipping (locally in excess of 25%) southern limb of the Warfield Anticline, and appears related to a late phase of extension involving folded Pennsylvanian strata. On a regional scale, the lithological variations across the fault do not suggest any appreciable strike-slip component.Underground room and pillar mines in the Coalburg seam north and south of the fault have been greatly impacted by the Warfield structures. Due to the combined (and opposite) effects of the folding and faulting, the northern mines are located up to 400 ft (125 m) higher in elevation than the southern ones. Overland conveyor belts connect mining blocks separated by the fault. The practical mining limit along the steep slopes toward the fault is around 15%. Subsidiary normal faults with offsets in the 5- to 15-ft (1.5–4.5 m) range are fairly common and form major roof control and production hurdles. Overall, the Warfield structures pose an extra challenge to mine development in this part of the Appalachian Coalfields.

II.—Notes on the Diamond-bearing Rock of Kimberley, South Africa

It may be fairly asserted that increased geological interest attaches to the deeper workings of the Kimberley Diamond Mines as they proceed. The remarkable development of underground mining, following upon the amalgamation of interests, which was the outcome of the collapse of the surface workings in 1886, or thereabout, has offered better opportunities for observation, not only of the diamond matrix-material but also of the varying characteristics of the neighbouring rock formations.