The surface of a fracture along which dislocation has taken place.
CF:fault plane
Two or more fault sets that were formed at the same time. CF:fault set
An irregular, terracelike tract between two fault scarps, produced on a
hillside by step faulting in which the downthrow is systematically on the
same side of two approx. parallel faults. CF:fault bench
See:fault line; rift.
A trap, the closure of which results from the presence of one or more
faults. AGI
See:fault line
See:rift valley
See:fault embayment
A mineral vein deposited in a fault fissure. Fay
A wedge-shaped block of rock between two faults. Stokes
Irregularities of gemstone crystallization and subsequent breakage or
separation, such as cleavage cracks, clouds, or feathers.
A fault that is expressed as a zone of numerous small fractures or of
breccia or fault gouge. A fault zone may be as wide as hundreds of meters.
CF:step fault
belt. AGI
The entire animal population, living or fossil, of a given area,
environment, formation, or time span. CF:flora
AGI
Of or pertaining to a natural assemblage of animals.
A triclinic mineral, (Zn,Cu)Al6 (PO4 )4 (OH)8
.4H2 O ; turquoise group; in fine grained apple-green masses in
Eureka County, NV.
A plunger-type jig, usually built with multiple compartments. It has three
distinguishing features: (1) plungers on both sides of the screen plate,
are accurately synchronized; (2) the refuse is withdrawn through kettle
valves near the overflow lips in the respective compartments; and (3) the
hutch is commonly discharged periodically by the operator by means of
suitable hand valves operated from the working floor. This jig is used
extensively on slack sizes of bituminous coal. Mitchell
A system of drilling that provides for the continuous removal of the
detritus from the well by means of a water flush or current of water.
Braz. In the diamond fields, brown pebbles consisting of a hydrated
phosphate, or of titanium and zirconium oxides; regarded as good
indications of the presence of diamonds.
The experienced prospector always seeks a favorable locality, which may be
in the neighborhood of a mining district or else in a locality that
contains favorable rocks and structures and appears as if it might contain
the mineral sought. See also:critical area
An orthorhombic mineral, 4[Fe2 SiO4 ] ; olivine group, with
iron replaced by magnesum toward forsterite or by manganese toward
tephroite; greenish-yellow to yellowish-amber; a common rock-forming
mineral in iron-rich metasediments, quartz syenites and granites,
ferrogabbro, and some felsic and alkaline volcanic rocks.