a. Uranium tetrafluoride. Lyman
b. A wood preservative consisting of copper, arsenic, and chromium
a. An unconsolidated marine sediment consisting largely of dark greenish
grains of glauconite, often mingled with clay or sand (quartz may form the
dominant constituent), found between the low-water mark and the inner mud
line. The term is loosely applied to any glauconitic sediment. AGI
b. A sandstone consisting of greensand that is often little or not at all
cemented, having a greenish color when unweathered but an orange or yellow
color when weathered, and forming prominent deposits in Cretaceous and
Eocene beds (as in the Coastal Plain areas of New Jersey and Delaware);
specif. either or both of the Greensands (Lower and Upper) of the
Cretaceous System in England, whether containing glauconite or not.
Syn:glauconite; glauconitic sandstone. AGI
A marl containing sand-size grains of glauconite. AGI
A schistose metamorphic rock whose green color is due to the presence of
chlorite, epidote, or actinolite. CF:greenstone
a. A field term applied to any compact dark-green altered or metamorphosed
basic igneous rock (e.g., spilite, basalt, gabbro, diabase) that owes its
color to the presence of chlorite, actinolite, or epidote.
c. An informal name for a greenish gemstone, such as fuchsite or
d. Compact, igneous rocks that have developed enough chlorite in
alteration to give them a green cast. They are mostly diabases and
diorites. Greenstone is partially synonymous with trap. It is often used
as a prefix to other rock names. The term is used frequently when no
accurate determination is possible.
e. Includes rocks that have been metamorphosed or otherwise so altered
that they have assumed a distinctive greenish color owing to the presence
of one or more of the following minerals: chlorite, epidote, or
f. Freshly quarried stone containing quarry water. Arkell
g. Can. Generalized name given to Precambrian lavas. Hoffman
Freshly exposed roof that is unknown in quality. Kentucky
A ferrous sulfate; copperas. Also called martial vitriol.
See also:melanterite; green copperas. Standard, 2
A formula used for calculating the thickness of tubbing: T = 0.03 +
HD/50,000, where T is the required thickness of tubbing in feet, H is the
vertical depth in feet, D is the diameter of the shaft in feet, and 0.03
is an allowance for possible flaws or corrosion. Sinclair, 2
A term used in Yorkshire, England, for a coarse-grained or gritty
An isometric mineral, Fe2+ Fe3+2 S4 ;
linaeite group; in minute grains and crystals in clays in the Kramer-Four
Corners area, San Bernadino County, CA.
A pneumatolytically altered granitic rock composed largely of quartz,
mica, and topaz. The mica is usually muscovite or lepidolite. Tourmaline,
fluorite, rutile, cassiterite, and wolframite are common accessory
minerals. See also:greisenization
A process of hydrothermal alteration in which feldspar and muscovite are
converted to an aggregate of quartz, topaz, tourmaline, and lepidolite
(i.e., greisen) by the action of water vapor containing fluorine.
Horizons in coalbeds resulting from temporary halting of the accumulation
of vegetal material. They are frequently marked by a bed of clay or sand.
A ditch or trench.
a. Two sets of uniformly spaced parallel lines, intersecting at right
angles, by means of which the surface of an area is divided into squares
when a checkerboard placement of boreholes is desired. Elevations may be
taken at line intersections. CF:checkerboarded
b. In surveying, a triangulation scheme that covers its area with a
network of acute-angled triangles drawn between mutually visible points.
c. A grated opening, as in a mining sieve. Zern
d. A network composed of two sets of uniformly spaced parallel lines,
usually intersecting at right angles and forming squares, superimposed on
a map, chart, or aerial photograph, to permit identification of ground
locations by means of a system of coordinates and to facilitate
computation of direction and distance. The term is frequently used to
designate a plane-rectangular coordinate system superimposed on a map
projection, and usually carries the name of the projection; e.g., Lambert
grid. Not to be confused with graticule. AGI
e. A systematic array of points or lines; e.g., a rectangular pattern of
pits or boreholes used in alluvial sampling. AGI
The framing at the top of a shaft for the pulley wheels or sheaves for the
hoisting rope. CTD
The angle at a given point in the plane of a rectangular coordinate system
between the central meridian, or a line parallel to it, and a straight
line to the azimuth point. AGI
A grinding mill in which a vertically suspended rolling disk rotates, and
under the influence of centrifugal force bears on ore passing between it
and a stationary bowl, crushing the passing ore on its way to a peripheral
discharge. Syn:pendulum mill
A ferroan variety of saponite.