The headings and levels excavated in a coal seam, preparatory to opening
out working faces. These drivages are planned to prove and render
accessible the maximum area of coal for the minimum yardage of development
work. The modern trend is to make in-the-seam development as productive as
possible with the aid of machines. See also:unproductive development
Nelson
Land that has produced farm crops within the previous 5 years.
Woodruff
a. A term closely allied with, and that may be expressed as, the output
per manshift of a face or colliery or metal mine. Productivity will vary
with the degree of mechanization and multishift working; it is also a
function of the horsepower, of a suitable nature, at the disposal of each
miner. See also:output
b. The efficiency with which economic resources (workers, materials, and
machines) are employed to produce goods and services. Crispin
a. The outline produced where the plane of a vertical section intersects
the surface of ground; e.g., the longitudinal profile of a stream, or the
profile of a coast or hill. Syn:topographic profile
b. A graph or drawing that shows the variation of one property such as
elevation or gravity, usually as ordinate, with respect to another
property, such as distance. AGI
c. Cross section of a region of cylindrical folds drawn perpendicular to
the fold axes. AGI
d. In seismic prospecting, the data recorded from one shot point by a
number of groups of detectors. AGI
e. See:soil profile
f. A vertical section of a water table or other potentiometric surface, or
of a body of surface water. AGI
g. A drawing used in civil engineering to show a vertical section of the
ground along a surveyed line or graded work. Webster 3rd
The technique of flying at a constant height above the ground during
airborne mineral exploration. Generally, the aircraft maintains a height
of 300 ft or 500 ft (91 m or 152 m) above the ground. This often involves
a series of skillfully controlled climbs and dives over rolling ground.
See also:vertical aerial photograph
A type of seismic refraction in which the shots and detectors are laid out
on long straight lines. Successive shots are taken at uniform or almost
uniform intervals along each line, and successive detector spreads are
shifted about the same distance as the corresponding shot points so as to
keep the range of shot-detector distances approx. the same for all shots.
Generally, shots are received from opposite directions on each detector
spread. The distance range is chosen so that the first, or where desired
the second, arrivals will be refracted from a particular formation such as
the basement or a high-speed limestone marker. The proper distance is
usually determined from time-distance plots based on experimental shooting
at the onset of the program. Dobrin
An instrument for plotting the perimeter profile of an airway on a reduced
scale, and primarily used when taking air measurements underground.
When one speaks of the interest on a mining investment, the rate mentioned
ordinarily consists of the normal rate plus a substantial additional rate
that represents the profit that should accrue in proportion to the
hazardous nature of the mining business. In this sense, the rate of
interest in most forms of mining should be high; to be satisfied with less
than 10% annually would show a lack of acumen. Hoover
Probable gross profit from a mine's ore reserves, as distinct from the
ground still to be blocked out.
Invoice that does not charge for goods marked, but shows cost details.
Pryor, 3
Metamorphic changes in response to a higher pressure or temperature than
that to which the rock last adjusted itself.
CF:retrograde metamorphism
A chart or graph forming a continuous record, which is kept up to date, of
the amount of work done on a major project. It may take the form of a bar
graph, divided into sections representing different jobs to be done,
estimated and actual completion dates, etc. The chart covers the entire
project from the initial site preparation or drivage to completion.
Nelson
See:Mono pump
In heat treatment, aging by increasing the temperature in steps or
continuously during the aging cycle.
See also:precipitation heat treatment
Rock or material failure in which the ultimate shearing resistance is
progressively mobilized along the failure surface. ASCE
Basic information needed by engineers concerned with design, site
development, machine and housing assembly, plant erection, contract
supervision, and coordination when planning, erecting, and bringing into
operation a new mine and its attendant services, including the ore
treatment plant. Pryor, 3
A pipe laid on the surface before building a fill that buries it.
Nichols, 1
a. In underground mining, a plan showing the proposed direction and
location of entries, rooms, shafts, fans, and watercourses. Such
projections commonly cover the entire property to be worked.
b. A systematic, diagrammatic representation on a plane (flat) surface of
three-dimensional space relations, produced by passing lines from various
points to their intersection with a plane; esp. a map projection.
AGI
c. Any orderly method by which a projection is made; the process or
operation of transferring a point from one surface to a corresponding
position on another surface by graphical or analytical means, so that each
point of one corresponds to one and only one point of the other.
AGI
d. See:exposure
e. See:outcrop
f. In mapping, a geometric (or mathematical) system of constructing the
true meridians and parallels, or the plane rectangular coordinates on a
map. Seelye, 2
g. A geometrically or mathematically derived portrayal of the surface of
the geoid on a plane surface. The requirement for a particular projection
is that it show the features of the surface of the Earth with a minimum of
distortion of distances, directions, shapes, and areas. Hy
h. The act or result of constructing a figure upon a plane or other
two-dimensional surface that corresponds point for point with a sphere, a
spheroid, or some other three-dimensional form. Fay
Shows movement of a pointer by means of an illuminated scale.
Pryor, 3
A series of plans of a proposed new mine or reconstruction, which are
drawn up for the purpose of obtaining approval of a project. BS, 7
A series of flat folds with near-horizontal axial planes contained
entirely within a bed with undisturbed boundaries.