McBride Mineralization

For complete information concerning the McBride River Property please click here to review in detail the November 2005 McBride River Geophysical Report prepared by Laurence Stephenson, P.Eng. and updated in April 2007.

General
The main deposit type that has been identified to date on the McBride Property is a high grade gold quartz vein. The presence of coarse placer gold in the region suggests that significant hydrothermal activity has introduced mineralizing solutions into the surrounding rocks. Two types of deposits could be related to this mineralizing event: 1) an epithermal gold vein deposit; and, 2) a buried intrusive porphyry. The presence of the volcanic sequences suggests the potential for a third deposit type similar to the Kutcho volcanogenic massive sulphides to the east and the observation of the author of the Report of the andesitic volcanic suggests a possible host of a Cyprus-style pillow volcanic hosted deposit.

Epithermal Gold Deposits
All examples of this deposit type are emplaced in volcanic arc environments in oceanic or continental margin settings. These deposits have close associations with other ore deposits that are typical of island arc environments. Consequently intrusion-related Au-(Ag-Cu) pyrrhotite veins should provide new exploration targets within established island arc-related porphyry and epithermal camps. Conversely, discovery of these high-grade gold veins in frontier areas should spur exploration for additional deposits of this type, and for all associated mineral deposit types of the volcanic island arc environment.

Veins may be composed of (i) massive fine-grained pyrrhotite and/or pyrite, or (ii) massive bull quartz with minor calcite and minor to accessory disseminations, knots and crystal aggregates of sulphides. Veins were emplaced progressively during normally-directed simple shear that accompanied a period of semi-brittle deformation. These two dominant vein types may occur independently or together, may grade into each other along a vein, may form parallel to each other in a compound vein, or they may occur in adjacent but separate veins within an en echelon set.

The subvolcanic setting for these deposits is transitional between the setting for porphyry copper systems and the setting for epithermal systems. Mineralization is synvolcanic and syn-intrusive and formed along the thermally "brittle-ductile transition envelope" that surrounds subvolcanic intrusions. Late magma movement generated localized shearing which opened en echelon vein sets. Circulating hydrothermal fluid precipitated gold-rich iron sulphides and gangue.

Quartz veins, stockworks and breccias carrying gold, silver, electrum, argentite and pyrite with lesser and variable amounts of sphalerite, chalcopyrite, galena, rare tetrahedrite and sulphosalt minerals form in high- level (epizonal) to near-surface environments. The ore commonly exhibits open- space filling textures and is associated with volcanic-related hydrothermal to geothermal systems.

Buried Porphyry Deposits
These deposits represent a transition from porphyry copper to epithermal conditions with a blending and blurring of porphyry and epithermal characteristics. Mineralization is related to robust, evolving hydrothermal systems derived from porphyritic, subvolcanic intrusions. Vertical zoning and superimposition of different types of ores is typical due, in a large part, to overlapping stages of mineralization.

Subvolcanic (hypabyssal) stocks, rhyodacite and dacite flow-dome complexes with fine to coarse-grained quartz-phyric intrusions are common. Dike swarms and other small subvolcanic intrusions are likely to be present. Country rocks range widely in character and age. Where coeval volcanic rocks are present, they range from andesite to rhyolite in composition and occur as flows, breccias and pyroclastic rocks with related erosion products (epiclastic rocks).

Veins are located near or above porphyry Cu hydrothermal systems and commonly contain pyritic auriferous polymetallic mineralization with Ag sulphosalt and other As and Sb-bearing minerals. Massive sulphide zones can pass outward into auriferous pyrite-quartz-sericite veins and replacements.

Volcanogenic Massive Sulphide Deposits
The main deposit type associated with this region is the Kuroko Noranda Volcanogenic Massive Sulphide class as found at Kutcho approximately 46 kilometres to the east of the property.

These island arc deposits are typically in a local extensional setting or rift environment within, or perhaps behind, an oceanic or continental margin arc. Marine volcanism, commonly during a period of more felsic volcanism in an andesite (or basalt) dominated succession is locally associated with fine-grained marine sediments and also associated with faults or prominent fractures.

Submarine volcanic arc rocks are rhyolite, dacite associated with andesite or basalt and less commonly, in mafic alkaline arc successions, associated with epiclastic deposits and minor shale or sandstone, commonly in close proximity to felsic intrusive rocks. Ore horizon grades laterally and vertically into thin chert or sediment layers called informally “exhalites." Vein and stockwork Cu (-Au) mineralization is associated with this deposit type.

A second type of deposit is suggested by the reported ande site agglomerate shear zone mineralization that the author of the Report property. The possibility that the mineralization is associated with pillowed volcanics is the rationale for this opinion.

Deposits typically comprise one or more lenses of massive pyrite and chalcopyrite hosted by mafic volcanic rocks and underlain by a well developed pipe-shaped stockwork zone. Lenses commonly are in tholeiitic or calcalkaline marine basalts, commonly pillowed, near a transition with overlying argillaceous sediments. Many lenses appear to be structurally controlled, aligned near steep normal faults. Their occurrence within ophiolitic complexes formed at oceanic or back-arc spreading ridges and possibly within marginal basins above subduction zones or near volcanic islands, within an intraplate environment could be consistent with the environment of the McBride Property.

Mineralization on the Mc Bride Property
Mineralization reported on the McBride Property is mainly associated with the quartz veins and “shear zones” in the andesite volcanics. Three vein zones and one shear zone were reported.

The vein zones were the Discovery Vein, the “B” vein and the D4 vein (“C”) and the Andesite Agglomerate is the shear zone. Most of the following information reported is based on the published assessment reports by Yeager and Ikona and Rayner and supplemented with the author’s own observations where appropriate.

Discovery Vein
This was first located in the 1981 field season and has had the most extensive hand trenching completed on it. Float samples led to the discovery of a 10 to 25 centimetre wide vein striking 30° and uncovered for 4 metres. Mineralogy was established by polished sections to be native gold, electrum, freibergite, and hessite in a quartz calcite vein with galena, sphalerite, chalcopyrite and arsenopyrite. The assessment reports by Yeager et al. provided most of this detail information and was completed in the early 1980's.

The host rock of the vein is “volcanic” greywacke with fragments of andesitic volcanics which in nearby outcrops are part of a sedimentary bedded sequence of greywacke, tuff and black shale. Individual beds are approximately one metre thick striking 138°/33° NE with one shale unit immediately to the northeast up to four metres thick.

The vein is within the regional 30° to 40° vertically dipping fracture system that in air photo linear is apparently strongest in a one kilometre wide zone passing through the discovery showing. The observations of the author of the Report confirm these trends.

Assays from the mineralized vein were reported of to 4.7 ounces per ton gold and 32.4 ounces per ton silver over 10 centimetres and 3.38 ounces per ton gold and 17.2 ounces per ton silver over 25 centimetres. Grab samples of much higher values have been reported but the whole vein is mineralized and open to further trenching. Assays from the host rock of 0.046 ounces per ton gold and 0.32 ounces per ton silver across 0.57 metres indicated that some mineralizing outside the vein by its emplacement had occurred.

Grab samples by the author of the Report returned values of 59.2 ppm gold, 137 ppm silver, 4.58% lead and 8.12% zinc and 0.59 ppm gold, 12.3 ppm silver, 1.21% lead and 1.22% zinc. The samples were described as a high grade sample of quartz vein with galena, light brown sphalerite, cubic galena, with calcite crystals and limonitic vein material from the rest of the vein. It was noted that very little difference was observed between the Discovery Vein and the “B” Vein in this fairly flat swampy area with the vein outcrop not prominent.

“B” Vein
This vein was uncovered in subsequent field work and is located approximately one kilometre to the southeast. The discovery of a float sample assaying 0.325 ounces per ton gold and 3.81 ounces per ton silver, led to the exposing of a mineralized quartz vein, traced for over 75 metres and ranging from 10 to 30 centimetres in width. Mineralogy of the white quartz vein was determined to be pyrite, chalcopyrite, galena and sphalerite and grab samples from the vein carried gold with silver.

Grab samples by the author returned values of 4.17 ppm gold, 62.9 ppm silver, 5.56% lead, 0.37% copper and 0.04% zinc. The host rock immediately adjacent to the vein was a medium-fine grained green massive, volcanic tuff, with jointing in the rock parallel to the vein (ridges and draws in the area are likewise parallel) with some minor 1-2 mm fragments observed. The vein material was white quartz with chalcopyrite, galena and pyrite ("B" Vein).

The host geology is tuffaceous andesitic agglomerates that host fragments of maroon and green volcanics. Sample MBLS-05-03 is described as a green andesite agglomerate with fragments up to 20 mm with maroon volcanic quartz eye in the fragments and a green volcanic fragments matrix of fine to medium grained green to pale green andesitic tuff material and like the “B” Vein host rock.

Joint structures are parallel to the vein and the surrounding gullies and draws at 25-30° with a near vertical dip. To the south in the surrounding andesite agglomerates joint structures at 118° with a slight south dip were noted. Fragments in the andesite agglomerate range from 1-2 millimetres to 20 millimetres.

D4 (“C”) Vein
This “zone” was discovered as well in subsequent field work on a stream, approximately 1.4 kilometres to the northeast of the Discovery Vein. Three mineralized fissure veins were uncovered which were 1-5 centimetres wide within obvious shear zones up to 0.5 metres in width. The quartz vein contains galena and sphalerite with gold values silver values. The host tuffs and shales were sampled over six metres returning 0.0 16 ounces per ton gold, again inferring that some mineralization into the surrounding rock has occurred.

Grab samples by the author returned elevated values of zinc (greater than 1 00ppm).

The rock looks more felsic (greywacke) with “joint” structures at 120° vertical and 38° slight west dip and 12° vertical with the main mineralized zone at 14° vertical.

The zone was perpendicular to the stream and covered by overburden within 1 – 2 metres from the stream. Further exploration on the uncovered portion would be of interest.

Andesite Agglomerate Shear
This zone was discovered in the latter part of the initial exploration program and work was done on it, apparently only in 1986. This zone is located approximately 250 metres west of the “B” Vein and another zone is reported to be 450 metres to the northwest of the “B” Vein.

The zone is reported by Ikona et al. as rusty mineralized shears with base metal sulphides in the andesite agglomerate unit. The agglomerate has sub angular to sub-rounded fragments up to 20 millimetres with some angular to sub-angular breccia type fragments up to 4 centimetres. The green andesite tuffaceous matrix was similar to that described above (MBLS-05-03). Two joint systems, associated with the mineralization, were identified striking 1 16°/78°S dip and 22°/72°E dip.

The mineralized zones appear to be in vuggy “veins” that have a distinctive form that suggests they are pillow selvages. Sample MBLS-05-4 was described as andesite agglomerate at the mineralized south end of the ridge and with jointing structure mineralization in joint structures trending 11 6°/78° 22°/72°. These vuggy veins with mineralization are suggested by the author to be pillow selvage rims with indicated tops to the south and near vertical look.

These “pillow” structures line up and suggest tops to the south with a vertical dip. Strike interpretation was not obvious.

Assays by previous exploration of up to 0.83 ounces per ton silver and between 0.75% to 1% for copper, lead and zinc were reported from these zones from hand dug trenches.

Grab samples by the author returned values of 0.0 14 ppm gold, 5.6 ppm silver, 4610 ppm lead, 270 ppm copper and 8770 ppm zinc and 0.023 ppm gold, 19.1 ppm silver, 742 ppm lead, 5740 ppm copper and 3280 ppm zinc.

Alteration on the McBride Property
Alteration of significance has been noted around the veins as limonite within the vein and peripheral to it. The limonite alteration extent into the surrounding host unit appeared very limited in extent at the “B” Vein and was not noted at the Discovery Vein. The “B” Vein has vuggy drusy cavities. The andesite agglomerate zone was associated with limonite, carbonate and jarosite alteration and malachite staining.