technical report on the nechalacho deposit, thor lake project ...

Table 8-1 continued
moderately altered;
primary minerals altered,
primary textures preserved
fresh or weakly altered;
primary minerals and textures
commonly preserved
magmatic
mineralizati
on
67 ZIRCONO-SILICATE CUMULATES (ALTERED) eudialyte/zircon pseudomorphs
cumulate. Some remobilization. (former
MRZ, 2b basal zone)
65 HETEROGENEOUS SYENITE (ALTERED)
63 FOYAITE II coarse-grained, foyaitic syenite
underlying cumulate zone
a - pegmatitic
61 K-FELDSPAR PEGMATITE
60 LAYERED SODIC SYENITES fresh, green aegirine and white
plagioclase (+/- nepheline)
a. aegirine nepheline albite syenite
b. sodalite nepheline syenite
c. aegirine nepheline K-spar syenite
49 SPOTTED AEGIRINE AMPHIBOLE SYENITE
48 BIOTITE SODALITE AEGIRINE SYENITE
47 LAYERED BIOTITE SODALITE ALBITE SYENITE
45 FOYAITE 3
43 SODALITE AEGIRINE AMPHIBOLE PEGMATITE
99 UNKNOWN
a - pervasive albitization - unknown precursor
b - pervasive mafic alteration - unknown precursor
c - pervasive fluorite-illite metasomatism
96 FAULT
97 BRECCIA
a. Green breccia unit
b. other
The primary peralkaline rocks have been altered by pervasive hydrothermal and metasomatic
fluids. This has resulted in the partial to complete replacement of the Nechalacho syenite unit in
the areas of mineralization. During metasomatic replacement a new assemblage of biotite,
magnetite, specularite, albite and/or chlorite is generated and these minerals tend to be
associated with the rare metals and rare earth elements within the resource. The last events in
the metasomatic sequence include the generation of microcline, albite and related silicification.
There is some suggestion that the early-formed rocks were affected by various forms of presolidification
displacement such as magmatic re-sedimentation, magmatic scouring, and
possibly foundering during cooling. The effect of these processes is to obscure lithological
correlations from cross-section to cross-section and give the impression of structural
displacement. In contrast, the metasomatic rocks generally show a good chemical correlation
Technical Report 43-101 – March 13, 2011 Page 8-4
Prepared by Avalon Rare Metals Inc.