An orthorhombic mineral, ZnSO4 .7H2 O ; in acicular or
hairlike crystals, or massive; a decomposition product of sphalerite on
recent mine workings at Butte, MT, and Bingham Canyon, UT. Syn:copperas;
white copperas; zinc vitriol.
An iron-bearing weathered product overlying a sulfide deposit. It is
formed by the oxidation of sulfides and the leaching-out of the sulfur and
most metals, leaving hydrated iron oxides and rarely sulfates.
Syn:capping; iron hat; chapeau de fer. Also spelled gozzan.
CF:oxidized zone; false gossan. AGI
Staff. Sudden bursting of coal from the face, owing to tension caused by
unequal pressure. The term "airblast" is sometimes used in metal mines,
esp. in South Africa. Zern; Fay
S. Staff. A system of working thick coal, being a kind of bord-and-pillar
plan, the main roadways being first driven to the boundary. Fay
a. An abandoned or exhausted mine. CTD
b. Coal ready to be filled underground into tubs or trains. CTD
a. A layer of soft, earthy or clayey, fault-comminuted rock material along
the wall of a vein, so named because a miner can "gouge" it out to
facilitate the mining of the vein itself. Syn:selvage; pug.
See also:gouge clay; hulk.
b. The clay or clayey material along a fault or shear zone. Also called
clay gouge. See:fault gouge
c. To work a mine without plan or system.
The angle at which the surface of a cutting edge in a drill bit is
inclined in relation to the surface of the material being cut.
See also:negative rake; positive rake. Long
Clay infillings in a mineral vein. CF:gouge
See:positive rake
a. In placer mining, an operation similar to ground sluicing. Also called
booming.
b. The formation of "crescentic gouges." AGI
c. The local basining of a bedrock surface by the action of glacier ice.
AGI
d. The working of a mine without plan or system, by which only the
high-grade ore is mined. Syn:high-grading
A gripping shot or opening shot used to make the first opening in a
straight-room face, or to start a breakthrough. See also:shot
Fay
Forest of Dean. Mine water containing hydrogen sulfide, H2 S.
Modification of the Helmholtz concept of the electrical double layer which
surrounds a particle immersed in an electrolyte. In Gouy's view there is
only one diffuse layer. The ionic atmosphere near the surface of the
particle is highly charged, but this ionization diminishes gradually
outward into the ambient liquid. Pryor, 3
A device for sinking shafts of small diameter through silt or clay without
excessive loss of ground. Hammond
See:gossan
An instrument for extricating broken boring tools from a borehole.
Fay
An excavator consisting of a crane carrying a large grab or bucket in the
form of a pair of half-scoops, so hinged as to scoop or dig into the earth
as they are lifted. CTD
An underwater digging device which, in closing, bites into the sediment
and contains it inside the closed shell. The bucket and load are then
hoisted to the surface where the shell is opened to dump the load.
Includes clamshells, orangepeels, and other variations. Mero
An ocean floor sampling system incorporating a large sediment grab with a
deep-sea camera. Hunt
A dredging appliance consisting of a grab or grab bucket suspended from
the jib head of a crane, which does the necessary raising and lowering.
Also called a grapple dredger. See also:dredger