The rock compounds of the area include: granite, granodiorite, monzonite and diorite with identified granular, porphyritic and granophyric
texture in microscopic thin section.
Patches of fine-grained granophyric
feldspar and quartz in central areas of the dyke usually show elongated needles of apatite.
The initial mapping conducted late 2010 and early 2011 on Treasure Island identified a granophyric
horizon in a dolerite/gabbro package of rocks, which indicated an environment with the right rock types, similar to that found further north in the belt at Kambalda and Kalgoorlie.
It is composed by strongly fractured granophyric
rocks, cross-cut by sub-vertical basic and acidic/felsic dykes with structural trend N65[degrees] and EW respectively.
A primary three-phase fluid inclusion assemblage contained within growth-zoned quartz crystals in the granophyric
phase of the Nipissing diabase was chosen as representative of the highest temperature fluids responsible for ore deposition at Cobalt.
The groundmass is granophyric
, partly spherulitic, and contains miarolitic cavities.
The drilling has intersected a previously unreported succession of layered mafic intrusive rocks including granophyric
gabbro, anorthositic gabbro, hornblende pyroxenite and olivine pyroxenite, containing up to 30 percent combined ilmenite and magnetite.
It also tends to be finer grained, and interstitial granophyric
texture is typically present.
17-57] from rim to core) in a fine-grained groundmass consisting of granophyric
quartz and K-feldspar.
From our initial mapping we identified a granophyric
horizon in a dolerite/gabbro package of rocks which indicated that we have the right rock types, similar to that found further north in the belt at Kambalda and Kalgoorlie.
(more wormy) to graphic (more cuneiform) intergrowths between feldspar and quartz are evident in three samples (DDH 79-6-174.
texture occurs only in samples from the northwestern part of the intrusion; that area may represent the shallowest part at the time of emplacement.