A form in the shape of a bunch of grapes. Syn:clusterite
botryoidal.
Having the form of a bunch of grapes. Said of minerals, e.g., hematite
with a surface of spherical shapes; also said of a crystalline aggregate
in which the spherical shapes are composed of radiating crystals.
CF:colloform; colloid minerals; reniform.
A radiated, columnar variety of datolite with a botryoidal surface.
Standard, 2
a. The floor or footwall of an underground mine.
b. The landing of a shaft or slope.
c. See:gutter
d. To complete a borehole.
e. To construct the bottom of or for; said specif. of underdraining a
level. Standard, 2
f. To strike bedrock or clay when sinking a shaft. Standard, 2
g. The landing at the bottom of the shaft or slope. Fay
h. The lowest point of mining operations. Fay
i. To underrun (as a gold deposit that is to be worked by the hydraulic
method) with a level for drainage. Webster 3rd
j. Surface in a borehole parallel to the face of a drill bit. Long
k. A mass of impure metal formed below the matte, in matting metal ores.
l. The footwall of a metalliferous deposit. Nelson
m. Barren bedrock. Nelson
n. The rock formation below the alluvium on which the gold or tin wash
dirt is met. Gordon
o. In gemstones, the pavilion.
p. Pennsylvania. The stratum, rock, or floor on which a coal seam lies.
Standard, 2
q. To break the material and throw it clear from the bottom or toe of the
borehole.
r. To place a drill bit in contact with the bottom of a borehole.
s. Surface in a borehole parallel to the face of a drill bit.
t. In metal-melting furnaces, this is usually the hearth or crucible.
See also:bottoming
Eng. Universally applied to the lowest bed in a quarry. Also used in
Southeast England for the basal bed of the Tertiary, whether Thanet sand
or Reading beds, resting on an eroded surface of the Chalk.
A belt conveyor that carries the coal or ore on the lower strand; often
used where height is limited. Nelson
The method by which the bench is removed from below as with a power
shovel. See also:benching
Technique by which sonar impulses are reflected off the ocean bottom one
or more times before reaching the target. Also refers to diving.
Hy
The break or crack that separates a block of stone from a quarry floor.
Hess
In leveling an underground roadway, a part taken out below a bed.
See also:canch
Coal below the undercut; it may or may not be removed.
a. A machine cut made in the bottom or floor of a seam before shot firing.
See also:cutting horizon; middle cut; top cut. Nelson
b. A drill hole pattern. See also:drag cut
c. In drilling and blasting a tunnel, the lower of two converging lines of
horizontally spaced holes. Upper line is draw cut. When blasted
simultaneously, a wedge of rock is removed. Pryor, 3
A dinter; a coal cutter for making floor cuts. Nelson
The diameter of a circle tangent to the seating curve at the bottom of the
tooth gap of a roller chain sprocket. Equal to the pitch diameter minus
the chain-roller diameter. Jackson, 1
bottom-discharge bucket conveyor
A conveyor for carrying bulk materials in a horizontal path consisting of
an endless chain to which roller-supported, cam-operated, bottom-discharge
conveyor buckets are attached continuously.
bottom-discharge conveyor bucket
A vessel generally rectangular or square in plan and having a bottom
consisting of an undercut gate.
See:mine car
A carrying scraper that dumps or ejects its load over the cutting edge.
Nichols, 1
Suitable for transporting free-flowing materials over a reasonably level
haul route that permits a high travel speed. They can be used where the
maximum flotation of a large single tire is required and where dumping in
windrows over a wide area is practical. See also:bottom dump truck
Carson, 1
A trailer or semitrailer that dumps bulk material by opening doors in the
floor of the body. Also called dump wagon.
See also:bottom-dump semitrailers
a. A completed borehole, or the point at which drilling operations in a
borehole are discontinued. Long
b. Said of shafts and slopes on being driven to completion when reaching
base of coal seam.