a. An abbrev. for chestnut coal. Also called nuts. Fay
b. Prepared bituminous coal that passes through 2- to 3-in (5.1- to
7.6-cm) round holes and over 3/4-, 1-, or 1¬-in (1.9-, 2.54-, or 3.2-cm)
holes, depending on the screening practice. Anthracite, through 1-5/8-in
(4.1-cm) and over 3/16-in (4.8-mm) round holes. Jones, 1
See:boulder buster
Letter name specifying the dimensions of bits, core barrels, and drill
rods in the N-size and W-group wireline diamond drilling system having a
core diameter of 54.7 mm and a hole diameter of 75.7 mm. The NW
designation has replaced the NX designation. Cumming, 2
The NX designation for coring bits has been replaced by the NW
designation. See also:NW
A generic term for a group of synthetic fiber-forming polyamides. The
polymer is melted, extruded, stretched, and finally processed to turn it
into a textile yarn having a very high strength, great powers of energy
absorption, and high resistance to abrasion and rotting. Its major uses in
mining are as a reinforcement for conveyor belting and ventilation
ducting. Nelson
A rubber belt containing nylon fiber reinforcing. It is stronger than
cotton-duck belts of equivalent size and possesses better troughability
and fastener holding strength. Nylon belt has the advantage of a long flex
life, and the thinner carcass means easier bending. Nelson
An eye disease suffered by some miners, in which there is a spasmodic
oscillatory movement of the eyeballs; in severe cases, the victim finds
difficulty in walking straight. Bad lighting is generally believed to be
the main cause, and is possibly aggravated by the workers lying on their
sides in thin seams. See also:mining disease
Loosely twisted fiber usually of hemp or jute impregnated with tar or with
a tar derivative (such as creosote or asphalt); used in caulking seams
(such as the wood hulls and decks of ships) and in packing joints (in
pipes, caissons, etc.). Webster 3rd
A white, granular limestone found in large quantities in Oamaru, New
Zealand, and valued as a building stone.
The overriding or overthrusting of oceanic crust onto the leading edges of
continental lithospheric plates; plate accretion. See also:subduction
AGI
See:objective
The lens (or lenses) that gives an image of an object in the focal plane
of a microscope or telescope eyepiece. Syn:objective lens;
object glass.
See:objective
See:objective
A quarry term applied to a block of stone bounded by 3 pairs of parallel
faces--4 of the 12 interfacial angles being right angles, 4 obtuse, and 4
acute.
A fault that strikes oblique to, rather than parallel or perpendicular to,
the strike of the constituent rocks or dominant structure.
CF:oblique-slip fault; strike fault; dip fault. Syn:diagonal fault
AGI
a. A joint whose strike is oblique to the strike of the strata or
metamorphic rocks in which it occurs.
b. A joint that forms an acute angle with dip joints and strike joints.
Lewis
The distance of a point from a main survey line measured at an angle to
the latter that is not a right angle. See also:offset
A pictorial view of an object showing its elevation, plan, or section to
scale with parallel lines projected from the corners, at 45 degrees or any
other angle, indicating the other sides.
See also:axonometric projection; isometric projection. Hammond
In a fault, movement or slip that is intermediate in orientation between
the dip slip and the strike slip. CF:strike slip