See:marlstone
An English term for calcareous shale; it is not a true slate. AGI
a. An indurated rock of about the same composition as marl. It has a
blocky subconchoidal fracture, and is less fissile than shale.
Syn:marlite
b. A term originally applied by Bradley (1931) to slightly magnesian
calcareous mudstones or muddy limestones in the Green River Formation of
the Uinta Basin, UT, but subsequently applied to associated rocks
(including conventional shales, dolomites, and oil shales) whose
lithologic characters are not readily determined. Picard (1953)
recommended abandonment of the term as used in the Uinta Basin.
AGI
c. See:marlstone ore
A stratified ironstone located in the Midlands (England) and occurring at
the top of the Middle Lias series. Nelson
Pertaining to, containing, or resembling marl; e.g., marly limestone
containing 5% to 15% clay and 85% to 95% carbonate, or marly soil
containing at least 15% calcium carbonate and no more than 75% clay (in
addition to other constituents). AGI
See:marmorization
Rock crystal variety of quartz.
A ferroan variety of sphalerite.
A thinly foliated variety of serpentine.
The conversion of limestone into marble by metamorphism.
Syn:marmarization; marmorosis.
See:marmorization
Obsolete term for marble. Arkell
An orthorhombic mineral, CaMn2 O4 ; opaque black with dark
red internal reflection; in Morocco.
A modification of the cyanide process in which the ore is deadroasted,
after which all of it is ground to slime, and the resulting product is
treated by agitation. Liddell
a. Well sinkers' term for a fine-grained floury rock, Oxfordshire, U.K.
b. Up to six workers who pool and share earnings equally, all at the same
workplace but not necessarily on the same shift.
An earlier type of miners' flame safety lamp fitted with two or three
conical gauzes, thus adding to the safety of the lamp when used in high
air velocities. The Marsaut lamp is the basis of modern flame safety
lamps. Nelson
A special, self-propelled geophysical vehicle designated to operate over
marsh or extremely soft ground, usually having wheels with very wide tread
or buoyant wheels that will float the vehicle in water. AGI
An appliance for measuring viscosity. It consists of a copper funnel,
about 30 cm long with a 15-cm diameter at the top, that has a 10-mesh
screen over half its diameter to remove debris and a 6-mm-diameter exit
tube at the bottom through which the rate of flow is timed. It takes 26 s
for a quart of clean water to flow through and correspondingly longer for
muds of greater viscosity. Gel strength is measured by comparing the rate
of flow of freshly agitated mud with that of mud that has been allowed to
remain quiescent for 10 min. See also:hydrometer;
specific-gravity hydrometer. Nelson
a. Methane, CH4 . If the decaying matter at the bottom of a marsh
or pond is stirred, bubbles of methane rise to the surface, thus the name
marsh gas. Nelson
b. It is nonexplosive until met with air or oxygen. In miners' language
synonymous with firedamp. See also:methane; firedamp. BCI; Fay
An isometric mineral. CuI ; soft; oil brown; dodecahedral cleavage; at
Broken Hill, New South Wales, Australia.
See:bog iron; bog iron ore.