Sandfire Resources N

PMY: McArthur Basin Diamond Drilling Update

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09/14/2017 | 01:19 am
14 September 2017


Managing Director

Simon Noon


Richard Monti (Chairman) Peter Harold (Non-exec.) Andrew Parker (Non-exec.)

Company Secretary

Patrick Holywell

Registered office

Level 10, 553 Hay St

Perth WA 6000


+61 8 6266 8642


+61 8 9421 1008


[email protected]

McArthur Basin Diamond Drilling Update



Borroloola West Joint Venture Project - Copper/Zinc/Lead/Cobalt/Silver

  • Diamond drilling completed at Mariner, and Coppermine Creek Prospects, designed to test for major primary copper and zinc-lead mineralisation.

  • Model of extensive stratiform, shallow, flat to gently dipping, zone of copper mineralisation confirmed at Coppermine Creek.

  • A previously unknown package containing pyritic black carbonaceous shales intersected at Mariner. Close association with observed lead and zinc mineralisation confirms potential for sediment hosted zinc-lead mineralisation.


The Borroloola West Joint Venture consists of 12 exploration licences and 1 mining licence (1,817 km2), The parties to the BWJV are 51% Pacifico Minerals Limited ("Pacifico" or "Company") (ASX code: PMY) and 49% Sandfire Resources NL ("Sandfire Resources") (ASX code: SFR).

Four of five holes, of a 1500m diamond drilling program, are now complete. Assay results are expected during the next 6 weeks.

Coppermine Creek

Two holes were drilled at Coppermine Creek, and both intersected visible copper mineralisation over significant widths (Figures 1 and 2).

CCD09 intersected approximately 13m of copper mineralisation from 123m depth. The hole was drilled 1.4km south of the Coppermine Creek Fault and confirms Pacifico's mineralisation model, developed from previous exploration drilling and ground EM survey conductivity profiles, that the copper mineralisation is stratabound, gently dipping and that there are large areas where the depths of this layer are at only 100m to 250m depth.

CCD10 intersected a broad zone of approximately 48m of copper mineralisation from 170m.

All the copper mineralisation is present as chalcopyrite which forms disseminations and lenses throughout the mineralised zones. No analyses have yet been received from the two holes. Of major significance is the large potential of the undrilled extent towards the south east (30km2) of the copper mineralisation (Figure 1), together with observation of widespread hematite, dolomite-silica and chlorite alteration. Targets for large economic concentrations of copper mineralisation can be defined adjacent to the major north-south or north-westerly trending faults running through the area (Figure 3).

All the mineralisation is hosted by the Amelia Dolomite which consists typically of finely bedded dolomite with carbonaceous laminae. Carbonaceous shales are locally developed. In parts of the sequence ex-anhydrite nodules and masses of ex-gypsum crystals are observed, now dolomitised. Chalcopyrite is concentrated within the evaporite rich part of the sequence, and often with zones of abundant carbonaceous laminae or crenulated carbonaceous algal mats.

Figure 1: Geology and drilling, including location of recently drilled diamond holes CCD09 and CCD10 at Coppermine Creek, also showing huge area potentially underlain by gently dipping mineralised horizon.

- 2 -

Figure 2: Section through recently drilled diamond holes CCD09 and CCD10 at Coppermine Creek Figure 3: Schematic section showing geological exploration model for copper mineralisation


Two diamond drill holes were completed at the Mariner prospect.

MND05 passed through Roper Group sediments, through a fault breccia zone, and into the Tooganinnie Formation consisting of moderately fractured dolomite. The fractures were often oxidised and contained limonite, cerussite (lead carbonate) and smithsonite (zinc carbonate).

MND06 drilled through a sequence of black carbonaceous, very pyritic shale and dolomite to 204m depth where the hole passed into Tooganinnie Formation dolomitic sediments. The hole is still being logged and assessed.

The combination of zinc and lead mineralisation in MND05, and a favourable pyritic shale host rock in MND06 are strong indications of potential for significant zinc mineralisation in the Mariner prospect area.


Diamond hole BJD04 has commenced at Berjaya, to test for McArthur River style stratiform zinc mineralisation. The Berjaya Prospect lies west and northwest of the world class McArthur River zinc-lead mine and Teck's zinc- lead resource at the world class Teena deposit (Figure 4). The diamond drill hole is designed to test a

Versatile Time Domain Electromagnetic ("VTEM") conductive horizon, that appears to correspond to the position of the overall gently dipping Barney Creek Formation beneath the Hot Springs Formation.

Lorella - Oxide and primary copper

An aircore program (2000m) is now planned for October to test strike extensions of previously drill intersected copper mineralisation, both for indications of significant down-dip primary sulphide mineralisation and for oxide copper mineralisation. The program is subject to preliminary metallurgical test work for acid leaching which is currently being carried out to ascertain if the oxide copper material could be economically viable.

Figure 4: Borroloola West Joint Venture Tenements (Pacifico 51%, and Sandfire 49%), ELA 31354 (Pacifico 100%), and prospects

Sandfire Resources NL published this content on 14 September 2017 and is solely responsible for the information contained herein.
Distributed by Public, unedited and unaltered, on 13 September 2017 23:18:03 UTC.

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