- A zone in which
contact metamorphism has taken place.
Source: Leet, L. Don. 1982.
Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall
- a. A circular or crescentic distribution pattern about the source or
origin of a mineral, ore, mineral association, or petrographic feature. It
is encountered principally in magnetic and geochemical surveys.
CF: dispersion pattern
b. Discoloration of a mineral, viewed in thin section, in the form of a
ring. Most haloes of this sort are caused by radiation damage by alpha
particles emitted from uranium- and thorium-bearing mineral inclusions.
c. A zone surrounding an igneous intrusion, in which the country rock
shows the effects of contact metamorphism. Syn: contact zone;
metamorphic aureole. AGI
d. A zone of alteration or other chemical reaction surrounding a mineral
in a rock.
e. See: halo
Dictionary of Mining, Mineral, and Related Terms