Coppermine Creek Results
- Results from recent drilling at Coppermine Creek confirm Pacifico may have drilled the fringe of a major copper mineralised system
- Results received from the three hole programme include:
* CCD03 10m @ 1.3% Cu from 68m, including 2m @ 4.0 % Cu
* CCR01 16m @ 0.5% Cu from 43m
* CCD02 23m @ 0.3% Cu from 136m
- High grades are contained in semi-massive chalcopyrite lenses, with only minor pyrite, and with textures very similar to those found at the world class Mount Isa copper deposit
- The mineralisation, alteration and key stratigraphic units intersected confirm the interpretation of the airborne EM conductivity profiles
- Planning underway to drill test the airborne EM high conductivity bullseye anomaly 2km south of the recent drilling
- Preliminary indications suggest that the metallurgy of any deposit found will be excellent, with coarse grained chalcopyrite, little pyrite, and only trace amounts of bismuth and arsenic
- Pacifico expects to meet its expenditure requirement to earn a 51% interest in the Borroloola West Project from Sandfire Resources NL once all costs for the recent program have been reconciled
Recently completed drilling intersected extensive zones of intense fracturing that contained disseminations and lenses of semi-massive chalcopyrite. All three drill holes intersected copper mineralisation and extend the known mineralisation along the east-west trending Gordons Fault by more than 300m west of previous drilling, for a total strike length of just over 500m.
Results from the recent drilling at Coppermine Creek indicate Pacifico may have drilled the fringe of a major copper mineralised system.
The first drillhole, CCR01, drilled reverse circulation ("RC"), intersected oxidised copper mineralisation in the hangingwall of the fault from 29m, grading 42m at 0.3% Cu (Table 1 in link below) with highest values of 5m at 0.8% Cu from 49m. Host rocks are Amelia Dolomite containing zones of intense fracturing, brecciation and dolomitisation. The hole was abandoned before entering the Gordons fault zone because of collapsing ground.
CCD02 was drilled 104m reverse circulation ("RC") and then diamond drilled to 315m. It intersected a significant interval of disseminated and veinlet chalcopyrite associated with a 10m thick bed of ex-evaporite, containing closely packed dolomitised gypsum casts, and contained 23m at 0.3% Cu from 136m, including 5m of 0.8%Cu from 147m. Minor disseminated chalcopyrite was also present throughout a zone of intense fracturing, brecciation and dolomitisation between 242m and 286m.
CCD03 (diamond drilling only) also intersected copper mineralisation associated with this same ex-evaporite bed with an intersection of 16m at 0.3% Cu from 40m, including 3m of 0.8% Cu from 40m. It then passed through the Gordons Fault zone which was intensely brecciated and dolomitised on the hangingwall, with lenses of semi-massive chalcopyrite, as well as chalcopyrite fracture fill and disseminations and contained 5m of 2.5% Cu from 68m, including 2m at 4.0% Cu from 71m.
The mineralisation and alteration, which contains disseminated sulphide comprising dominantly chalcopyrite, is reflected in AEM ("Airborne Electromagnetic") conductivity profiles that indicate a broad zone of alteration and disseminated mineralisation extending for 3km x 1km, south from the Gordons Fault. It is interpreted from Pacifico's drilling that the stratabound copper mineralisation near the Gordons Fault outcrops because it has been pushed to the surface by a post-mineralisation reverse fault that rides over younger Roper Group sediments. Bedding dips are steeper close to this reverse fault and gently flatten away to the south.
The 1km x 300m bullseye of relatively high AEM conductivity that lies 2km south of Pacifico's recent drill holes is now a compelling target. This may reflect intense chalcopyrite stockwork veining and lenses at depths from 250m to over 600m. Gossanous material overlying the western part of the bullseye AEM anomaly contained 0.3% Cu (from qualitative portable X-Ray Fluorescence instrument ("pXRF") determinations) and confirms the presence of copper mineralisation. It is possible that supergene copper mineralisation may be developed in the oxide zone below the level of leaching.
Supporting the opportunity for the presence of a major copper mineralised system of the Mount Isa Copper (approximately 250Mt of 3%Cu) or Nifty (approximately 100Mt of 2%Cu) style are the following key geological factors:
- Distinctive ex-evaporite beds in the overlying Amelia Dolomite contain disseminated copper mineralisation.
- The mineralisation is close to the redox contact between hematitic siltstones (oxidised) of the Mallapunyah Formation, and the overlying Amelia Dolomite.
- Reverse faulting at Coppermine Creek indicates that copper mineralisation could be related to a compressive regional event.
- The copper mineralisation appears to be spatially related to a major north-south trending regional fault system that may provide access to copper-bearing basin fluids.
- Intense fracturing, brecciation and dolomite (- silica) alteration is widespread and related to the copper mineralisation.
- Coppermine Creek lies within the McArthur Basin, where there are known large base metal mineralised systems, in an area that has only been patchily explored previously.
Pacifico's Managing Director, Simon Noon, comments "these are highly encouraging results. To date drilling has only tested the northernmost margins of a system that appears from the airborne EM to extend for at least 3km to the south, parallel to a major regional fault system, and where a gossan has been recently discovered containing anomalous copper. The bullseye of the EM anomaly is now a compelling target for drilling".
Pacifico expects to meet its expenditure requirement to earn a 51% interest in the Borroloola West Project from Sandfire Resources NL (ASX:SFR) once all costs for the recent program have been reconciled. Under the terms of the farm-in agreement Pacifico can earn up to 80% interest in the project.
Pacifico has now completed its two-hole drill program at the Bing Bong prospect where 50% of the direct drilling costs were covered by the NT government. Minor pyrite was observed in places within a thick sediment package to depths up to 400m. However, preliminary visual inspection of the core failed to explain the source of the magnetic and AEM anomalies targeted. Final assay results are still pending.
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About Pacifico Minerals Ltd
Pacifico Minerals Ltd (ASX:PMY) is a Western Australian based exploration company focussed on advancing the Berrio Gold Project located in Colombia. Berrio is situated in the southern part of the prolific Segovia Gold Belt and is characterised by a number of operational, artisanal-scale adits, tunnels, and declines. The project is 35km from the Magdalena River which is navigable to the Caribbean Sea and has excellent infrastructure in place including hydro power, sealed roads, water supply and telecommunications coverage. Pacifico also has an interest in two other projects in Colombia (Natagaima and Urrao) and one project in the NT, Australia (Borroloola West Project).
Sandfire Resources NL
Pacifico Minerals Ltd