a. Composed of columnlike individuals. Schieferdecker
b. A mineral with a form obscurely resembling prisms, e.g., hornblende.
See also:prismatic
c. In columns produced by shrinkage joints, as in columnar basalt.
a. A charge of explosives in a blast hole in the form of a long continuous
unbroken column.
b. A continuous charge in a quarry borehole. CF:deck charge
BS, 12
Elongated crystals that grew at right angles to a surface. CMD
Parallel, prismatic columns, polygonal in cross section, in basaltic flows
and sometimes in other extrusive and intrusive rocks. It is formed as the
result of contraction during cooling. Syn:columnar structure
AGI
A geologic illustration that shows in a graphic manner, and by use of
conventional symbols for different rock types, the successive rock units
that occur throughout a given area or at a specific locality. It may be
accompanied by a very brief description of lithology and by appropriate
brief notations indicating the thickness, age, and classification of the
rocks. See also:geologic column
a. A mineral fabric consisting of slender crystals of prismatic cross
section, as in some amphiboles.
b. See:columnar jointing
c. Columns, 9 to 14 cm in diameter and 1 to 1.4 m in length, found in some
calcareous shales or argillaceous limestones; oval to polygonal in
section. Columns are perpendicular to bedding. Possibly a desiccation
structure. Pettijohn, 1
a. A pneumatic flotation process with a counter-current flow of rising
bubbles against settling ore within the flotation cell. Typically, the
cell height is much greater than the cross section of the cell. The feed
slurry is input above the midpoint of the column and water sprays are used
at the top of the froth column to remove entrained hydrophilic particles
from the froth. Kelly
b. Flotation carried out in a column machine utilizing countercurrent flow
of air bubbles from the bottom and solid reagent-conditioned material from
the top, such that tailings are withdrawn at the column bottom and the
concentrate is collected over the column lip. There is no mechanical
agitation. SME, 1
The length of each portion of a blast hole filled with explosive
materials. Atlas
Simulation of in-situ leaching through the use of a long narrow column in
which ore sample and solution are in contact for measuring the effects of
typical variables encountered in actual in-situ leach mining.
SME, 1
A single continuous charge. Carson, 1
See:mud column
A deposit of ore in a lode having a small lateral, but considerable
vertical extent. An older term for ore shoot.
The large cast-iron (or wooden) pipe through which the water is conveyed
from the mine pumps to the surface. Syn:mounting pipe; rising main.
a. A variety of tetrahedrite containing 3.21% tin, from Japan.
Spencer, 4
b. An isometric mineral, Cu26 V2 (As,Sn,Sb)6 S (sub
32) ; in bronze-colored tetrahedra, from Butte, MT.
Said of igneous rocks that have a common set of chemical and mineralogic
features, and thus are regarded as having been derived from a common
parent magma. See also:consanguinity
AGI
An area in which the igneous rocks are of the same general geologic age,
have certain distinguishing characteristics in common, and are regarded as
comagmatic. Syn:petrographic province
In a fissure that has been filled by successive deposits of minerals on
the walls, the place where two sets of layers thus deposited approach most
nearly or meet, closing the fissure and exhibiting either a drusy central
cavity or an interlocking of crystals. See also:comb texture
See:comedown
In its simplest form this structure consists of a fissure lined with
crystals on each side, having their bases on the walls and their apexes
directed toward the center. In some cases the fissure is thus altogether
filled up with two sets of crystals meeting in the center.
A trigonal mineral, Na2 Ca2 Si3 O9 ; in
nephelinite at Kivu, Republic of the Congo.
A drill equipped for cable-tool and/or diamond-drilling operations, or for
a cable-tool and/or rotary drilling operations. Syn:combination rig
Long