NI43-101Pre-Feasibility Study Report - page 120

Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
, 2014
10135-200-46 - Rev. 0
sulfides, Fe
Ti oxides, and REE and thorium minerals. Sulfide and oxide minerals
include pyrite, pyrrhotite, chalcopyrite, specularite, galena, sphalerite, and rutile.
Silicocarbonatite occurs often as contact zones enveloping a sovitic carbonatite core.
earth mineral abundances in carbonatite range from trace amounts to more than
20%, while REE minerals tend to be significantly less abundant in silicocarbonatite.
Intrusive breccia: Intrusive breccia has a rock flour matrix enveloping abundant clasts
of trachyte and phonolite ± minor pseudoleucite, lamprophyre, and syenite porphyry
clasts. The unit can be either matrix or clast supported. Heterolithic intrusive breccias
occur as diatremes, and as small dike
like bodies. Carbon Hill and Bull Hill are the two
most important examples of large diatremic breccia bodies. (Note: A diatreme is
defined as a breccia
filled volcanic pipe that was formed by one or more gaseous
Intrusion breccia: The intrusion breccias are composed of trachytic or phonolitic clasts
dispersed in an igneous matrix of the same composition. Intrusion breccias are often
contact breccias along the margins of intrusive bodies.
Pseudoleucite porphyry: Pseudoleucite porphyry occurs as small dikes that post
trachyte/phonolite, and as rare clasts within parts of some heterolithic breccias. The
porphyry is characterized by pseudoleucite and sanidine phenocrysts set in a dark
brown to greenish grey, fine grained groundmass of devitrified glass, nepheline, K
feldspar, biotite, sodic pyroxene, and sulfides. Andradite garnet can occur rarely as
both phenocrysts and groundmass. Pseudoleucite porphyry and heterolithic intrusive
breccia host low
grade gold mineralization in the East and West Breccia deposits in
Section 21.
phonolite porphyries: Trachyte
phonolite porphyries form stocks and sills in
the core of the intrusive complex and are the most abundant lithology type. Trachyte
and phonolite are associated with syenite in parts of the complex, and they can be
found as extrusive flows locally along the outer margin. Trachyte and phonolite are
often difficult to distinguish in the field, owing to fine grains size and/or hydrothermal
Unoxidized trachyte and phonolite are light to dark grey or greenish grey in color. They
contain sparse to abundant sanidine phenocrysts ± subordinate phenocrysts of
clinopyroxene, biotite, and/or feldspathoids dispersed in a fine
grained, aphanitic
groundmass of alkali feldspar ± devitrified glass, nepheline and/or sodalite, biotite,
augite, alkali amphibole, and/or sulfide. Both trachyte and phonolite may exhibit
trachytic texture. Disseminated pyrite is common. Phonolite is distinguished in the field
by the presence of feldspathoid phenocrysts. Some of the trachyte is carbonate
flooded at the surface and at depth.
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