A coarse-grained, deep-seated ultramafic rock, consisting essentially of
garnet (almandine-pyrope) and pyroxene (omphacite). Rutile, kyanite, and
quartz are typically present.
The study of the relationships between organisms and their environment,
including the study of communities, patterns of life, natural cycles,
relationships of organisms to each other, biogeography, and population
changes. Adj: ecologic; ecological. Syn:bionomics
The reserves in coal seams that are believed to be workable with regard to
thickness and depth. In most cases, a maximum depth of about 4,000 ft (1.2
km) is taken, and a minimum thickness of about 2 ft (0.6 m). The minimum
economic thickness varies according to quality and workability.
See also:thin seam
The reduction in the value of a mineral deposit as the minerals reserves.
See also:depletion
The study and analysis of geologic bodies and materials that can be
utilized profitably by humans, including fuels, metals, nonmetallic
minerals, and water; the application of geologic knowledge and theory to
the search for and the understanding of mineral deposits. AGI
An arrangement to preheat the feedwater before it enters the steam boiler.
The water flows through a bank of tubes placed across the flue gases as
they leave the boiler. Nelson
A dynamic community of biological organisms, including humans, and the
physical environment with which they interact. SME, 1
A circular movement of water. Eddies may be formed where currents pass
obstructions or between two adjacent currents flowing counter to each
other. Hy
Arrangement by which internal currents are induced in a mass of metal as
it moves relative to a magnetic field. Pryor, 3
A nondestructive testing method in which eddy-current flow is induced in
the test object. Changes in the flow caused by variations in the object
are reflected into a nearby coil or coils for subsequent analysis by
suitable instrumentation and techniques. ASM, 1
A German term for a shoot of precious-metal ore.
See:aedelforsite
See:prehnite
A monoclinic mineral, NaCa2 (Mg,Fe)5 Si7 AlO22
(OH)2 ; amphibole group with Mg/(Mg + Fe2+ ) = 0.5 to 1.0;
named for the type locality, Eden, NY.
In a crystal, a row of atoms or ions marking the edge of a
crystallographic plane extending only part way. CF:line defect
The working of steeply inclined coal seams, many features of which are
comparable to metal mining. See also:stope
A conglomerate exhibiting edgewise structure; e.g., an intraformational
conglomerate containing elongated calcareous pebbles that are transverse
to the bedding. See also:edgewise structure
A primary sedimentary structure characterized by an arrangement of flat,
tabular, or disk-shaped fragments whose long axes are set at varying steep
angles to the bedding. It may be due to running water or to sliding or
slumping soon after deposition. See also:edgewise conglomerate
AGI
See:prase; mother-of-pearl.
a. Titanic acid, rutile, occurring in golden-brown, orthorhombic crystals.
Fay
b. An early name for rutile.
The exhaust pipe from the low-pressure cylinder to the condenser.
Fay