Summary:
The Carosue Dam Operations (CDO) assets include the Carosue Dam Project (comprising the Karari and Whirling Dervish gold deposits), the Porphyry Project (consisting of the Porphyry, Million Dollar, Enterprise and Wallbrook gold deposits) and the Deep South Project (consisting of the Deep South, Safari Bore and Moody’s Reward gold deposits).
Karari-Dervish
The Karari-Dervish deposits are lithologically and structurally controlled and have been offset along a series of major faults running NE-SW and NW-SE, as well as intruded by large lamprophyre units post mineralization. The lithology comprises primarily of intermediate felsic volcaniclastic sandstones, intermediate tuffs and intermediate porphyry units intruded by granites of varying composition, with stratigraphy dipping generally to the east at ~ 60 degrees. Mineralisation is dominated by pyrite and hosted in broad hematite altered sandstone units with a central high grade siliceous core light-moderately dipping to the North.
Dimensions
Mineralisation at Karari-Dervish has continuity over 1000m along strike, 1100m down dip and 250m across strike. High grade mineralisation is controlled by 60° East dipping shear zones. Mineralisation is hosted within extensive quartz vein breccia zones adjacent to the shears. The high-grade mineralisation is associated with intense haematite, silica and sericite alteration that occurs predominantly where flatter cross-linking structures intersect with the steeper dipping shears.
Porphyry
Mineralisation, especially high gold values is associated with intense shearing and confined to thin, intensely sheared bands approximately 10cm thick. The edge of the mineralisation feathers out into multiple, thin low grade bands. Generally, a halo of weak sheared and carbonatisation envelope the strongly sheared and mineralised zone of quartz-pyrite veining and hematite alteration.
The most obvious guides to gold mineralisation are shearing, quartz-pyrite veining and strong hematite alteration. Mineralisation is structurally controlled. The deposit is segregated into a series of lenses, with the largest measuring 400m by 150m. The ore lenses maybe separated by faults, but are generally stacked en echelon. Within each lens, the distribution of gold mineralisation is a complex series of en echelon sub-lens of 20m to 40m in width, segregated by waste bands. The lenses contain ore pods that strike perpendicular to the orebody and may dip approximately 40° south. (Smith, 2004). Ore lenses also step to the right in longitudinal section suggesting sinistral movement on the north-south portion of the mineralised structure.
Dimensions
The gold mineralisation at Porphyry strikes about 1.6 km in length spanning over an area with 900m in width. The mineralisation extends to below 300m below surface.
Million Dollar
Gold mineralisation is associated with albite-silica-hematite-sericite-pyrite alteration and quartz pyrite veining. Structural controls on the mineralisation are shallow easterly dipping north striking brittle shear zones related to the NNW trending regional faults. The thickness of the shear zones vary between 1m and 10m wide.
Dimensions
Million Dollar mineralisation extends from 6,704050mN to 6,702,450mN, 430,800mE to 431,400mE and 260 metres below surface.
Enterprise
The Enterprise mineralisation lies within a synformal, south plunging (25 degree) zone that is postulated to occur at the intersection of strongly deformed andesites occurring within N-S trending shear/fault zones. These structures dip moderately to steeply to the east and a series of quartz stockwork vein arrays trending NNW (330 to 340 deg) dip steeply to the west. This mineralised system forms pipe-like bodies, which plunge gently to the south.
Dimensions
The mineral resource extends a 1.3km strike extent area to 200m below surface, with MGA coordinates stretch from 6704400mN-6705750mN, 433600mE- 433900mE and 380mRL – 242.5mRL. Within that area the main ore lodes commonly dip moderately to the west with a steeper east dipping lode on the eastern margins.
Wallbrook
At Wallbrook a mineralised quartz vein stockwork has developed within and adjacent to a small syenogranitic intrusion within metabasalt. Locally however, the wall rocks at Wallbrook comprise relatively incompetent felsic schists. Quartz veins formed a conjugate set while the local principal stress axis was oriented northeast – southwest.
Dimensions
Redbrook, Eleven Bells and Red Flags deposits stretch from 6694800mN to 6696350mN and 433800mE to 434400mE to 300m below surface. The ore lodes have strike lengths from 25m to 260m and plunge extents and widths up to 330m.
Deep South
Mineralisation occurs in two loads concordant to geology, the Butler and Scarlett lodes, and is confined between layered metasedimentary and felsic volcaniclastic units on both the hanging wall and footwall. The two lodes are separated by a high magnesium basalt and an ultramafic unit. The Butler lode is located in the hanging wall and is strongly silica and pyrrhotite-pyrite altered, and well laminated (appearing like a BIF within the oxidise portion). The contrasting physical properties of this unit to the surrounding unit have created fluid pathways and traps, as well as the high iron content of the unit providing a chemical trap, for gold deposition.
The Scarlett lode is strongly weathered in the upper oxide portion to a gossanous material comprising hematite, goethite and quartz fragments. Weathering at Deep South has been preferential along Scarlett lode due to its high carbonate content. Where fresh, the lode is a fine grained banded carbonate unit with variable pyrrhotite, pyrite and magnetite. It is weakly foliated in line with the regional foliation.
Dimensions
Both mineralised lodes at Deep South have continuity over 500m along strike and 400m down dip. The Scarlett lode averages 5m in width and the Butler lode averages 2m in width. Both lodes strike North north-west and dip steeply at 75 degrees to the west. The higher grade plunge direction is to the north, pitching 70 degrees in the Scarlett but more steeply at 80 degrees in the Butler. The south plunging shoot in the Scarlett pitches at approximately 65 degrees.
Safari Bore
Mineralisation within this sequence occurs in multiple structural and lithological settings, in four discreet lodes (red, green, purple and Serengeti), all associated with quartz-carbonate-albite hydraulic breccia veins. Serengeti and red lodes lie within the margins of gently southerly plunging felsic porphyry. Green and purple lodes are sub vertical sheets oriented sub-parallel to foliation.
Dimensions
The gold mineralisation at Safari Bore strikes about 1.3 km in length spanning over an area with 300m in width. The mineralisation extends to below 280m below surface.
Moody’s Reward
Locally the geology of the Moody’s Reward area consists of intermediate schists and igneous intrusives adjacent to sediments. Basaltic andesite, felsic volcanics and volcaniclastics trend in a north west- south east direction.
Dimensions
The zone of mineralization extends for approximately 1500 m along strike, 3 to 30 m across strike and from near surface (1-2 m BSL) up to 180 m vertically. The mineralisation stretches from 6756400mN-6754700, 429400mE-429700mE and 180mRL to 387mRL.