Introduction

The Rooderand Project is located on the western limb of the Bushveld Complex on the farm Rooderand 46 JQ, Portion 2, which is in the North West Province of South Africa, 150 kilometres (km) north-west of Johannesburg. 

The project comprises of a land area of 556 Ha adjacent and is situated adjacent to Platmin’s Pilanesberg open pit platinum mine.  Merensky and UG2 reefs are known to be present on the property and a resource estimate for these reefs was established by the previous owners.

Under a Heads of Agreement signed in March 2009 with Atla Mining Resources (Pty) Ltd, PLA has acquired an initial 30% interest in the Rooderand Project for making an initial payment of ZAR13.5 million and will acquire a further 35% for funding and completing a Definitive Feasibility Study on the project. PLA can then earn a further 5% interest in the project for arranging the financing for the development of the project. PLA, through its South African subsidiary, Platinum Australia SA has been appointed as the manager of the project.

A Prospecting Right was issued for the project in November 2009 and PLA immediately commenced a resource definition drilling program in the same month.

Current Resource

The previous owner, Anglo Platinum established an Inferred Resource for the project as follows:

Reef                Tonnes             Grade                Ozs
                           Mt                 g/t 4E             Moz 4E

UG2                  11.8                 5.39                2.05
Merensky           3.8                 7.99                0.97

Regional Geology and Mineralisation

The PGM mineralisation is hosted with the approximately 2.0 billion year old Bushveld Igneous Complex (BIC). The BIC is composed of approximately seven to nine thousand metres of magmatic rocks exposed in three limbs, the Western, Eastern and Northern Limbs. The mafic to ultramafic layered rocks are known as the Rustenburg Layered Suite (RLS) and have been divided into five zones known as the Marginal Zone, Lower, Critical, Main and, Upper Zones (Figure 1). The Critical Zone is characterised by regular rhythmic layering of cumulus chromite within pryoxenites, anorthosites, norites and, olivine-rich rocks. It is these mafic rocks that host layers rich in platinum group elements (PGMs), chromium and vanadium. In addition nickel and copper are generally associated with the deposits and are significant by-products.

 Figure 1. Geology of the Western Bushveld Complex (click image to enlarge)

The economically viable reserves of the BIC are hosted within the Critical Zone of the RLS. The Critical Zone consist of all 14 chromitite layers of the BIC, the upper most of which is the UG2, averaging less than 1m in thickness, and contains economic concentrations of PGE-bearing minerals. The PGMs are composed of varying proportions of platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir) and osmium (Os) metals, and are often associated with elevated concentrations of gold (Au), nickel (Ni), copper (Cu) and cobalt (Co).

The two upper most units of the Critical Zone are the Merensky and Bastard cycles, of which the Merensky is of economic importance,  as at its base it hosts the PGE-bearing Merensky Reef, a pegmatoidal feldspathic pyroxenitic assemblage, associated with thin chromitite layers and disseminated sulphides.

In the northern areas of the Western Limb of the BIC several metres below the Merensky Reef a unit known as the Pseudo Reef occurs The Pseudo Reef consists of two distinct portions: the Lower Pseudo Reef, a coarse-grained pegmatoidal feldspathic harzburgite, and the Upper Pseudo Reef, a finer grained feldspathic harzburgite. The Pseudo Reef may contain significant concentrations of PGMs.

Local Geology and Mineralisation

In the Rooderand Project area rocks of the Critical Zone are present and generally strike north-south and dip between 10  to 20 to the east. The BIC is intruded by the younger Pilansberg Alkaline Complex (PAC) (1.3 billion years old). During the emplacement of the Pilansberg Complex, the rocks of the BIC were significantly faulted and displaced. Several alkaline dykes related to the Pilansberg Complex intrude the BIC.

The stratigraphic sequence present at Rooderand is thought to be very similar to that at Union Section Mine (20 km to the NE) as well as the Amandebult and Northam mines (approximately 50km NE). The mineralised horizons that are being targeted at the Rooderand Project are (in stratigraphically descending order, Figure 2). 

•  Merensky Reef (MR),
• the Merensky Footwall Mineralisation (MRFW),
• Upper (UPR) and Lower Pseudo Reefs (LPR),
•  Pseudo Harzburgite Mineralisation (PRHZB) and
• UG2 Chromitite Layer.

Where the sequence has been fully developed the vertical distance between the top and bottom of the reef package varies between 20m to 30m. This interval may be significantly reduced by potholing and faulting. The MR and to UG2 Chromitite Layer interval in the Rooderand area differs markedly from elsewhere in the BIC where this interval may be separated by well over 100m. Where this attenuated sequence are close together and the Pseudo Reef is well developed is termed the Swartklip Facies.

Figure 2. Generalised stratigraphy of the BIC at Pilanesberg (Click image to enlarge)

The UG2 Chromitite Layer is the most consistently developed mineralised horizon in the Rooderand Project area and is generally less than 1m thick, and is comprised of 60% to 90% chromite. The PGMs occur interstitially to the chromite grains. The PGM content of the UG2 Chromitite Layer ranges from 3 g/t to 19 g/t and is generally dominated by Pt-Pd sulphides. The grade distribution within the UG2 is not uniform throughout the BIC, in the north-western BIC the peak PGM values occur at the bottom and near the middle of the UG2 compared to other parts of the BIC. Above the UG2 Chromitite Layer is a very characteristic olivine pyroxenite up to 1.5m thick, and in turn is overlain by the UG2 Chromitite Layer hangingwall pyroxenite.

The MRFW mineralisation tends to develop in anorthosite where potholing of the MR has occurred. This style of mineralisation is well developed in the adjacent Tuschenkomst deposit. The PGM mineralisation is discordant and associated with sulphide development in the anorthosite.

The MR is a feldspathic pegmatoidal pyroxenite, bounded top and bottom by thin chromitite bands. The platinum group minerals (PGMs) that occur within this reef are predominantly PGM-iron alloys and PGM-sulphides. Where the MR has been potholed the MR occurs as a single chromitite stringer at the base of the MR hangingwall pyroxenite and is classified either as Contact Reef (MRC) or Pothole Reef (MRP). The MRC is where the reef has not potholed all the way down onto the UPR and some mottled anorthosite has been preserved. The MRC is characterised by a thin chromitite stringer overlying a well developed anorthosite footwall unit that may contain erratically developed mineralisation. In the MRP the MR chromitite and the UPR chromitite have coalesced and the anorthosite footwall has been entirely removed.

The MR is overlain by a cyclic unit consisting of pyroxenite, norite and anorthosite units. Above this is the Bastard cyclic unit consisting of pyroxenite, norite and, mottled anorthosite units. The mottled anorthosite unit capping the Bastard cyclic unit contains extremely coarse mottles (5cm to 10cm in diameter) and is known as the “Giant Mottled Anorthosite”.

Where the MR has been potholed onto the UPR, discordant PRHZB mineralisation may occur within the harzburgite that separates the UPR and LPR.

The Pseudo Reef as the name suggests is very similar to the Merensky Reef, but is relatively weakly mineralised and contains minor amounts of base metal sulphides. The Pseudo Reef horizon lies above the UG2 Chromitite Layer hangingwall pyroxenite. The Pseudo Reef is a distinctive feldspathic harzburgite layer, bounded by thin chromitite layers.

The Pseudo reef is comprised of the Lower Pseudo Reef (LPR) a pegmatoidal olivine pyroxenite) up to 1.5 m thick), Pseudo Reef Harzburgite (Tarentaal Harzburgite) a poikolitic feldspathic harzburgite (up to 6m thick) and the Upper Pseudo Reef, a pegmatoidal pyroxenite (up to 50cm thick).

IRUPS in the form of dykes, pipes and sheets are not a common feature in the RLS at the neighbouring Pilanesberg deposit.

Work Programme

Diamond Drilling

PLA commenced a drilling programme on the Rooderand Project area in late November 2009, and by June 2010 had completed almost 200 holes. The drilling is part of a planned 25,000 metre programme that will provide PLA with sufficient information to complete resource estimation to a Definitive Feasibility Study Level. As well as being logged for the lithologies and reefs, the structural information such as the presence of faults, joints and RQDs are being captured. This information will be used in the overall mine design (both open pit and underground) for the Rooderand Project.

Figure 3. Location of Rooderand Project (Click image to enlarge)

Ground Magnetics

Spectral Geophysics (Botswana) were contracted to undertake a detailed ground magnetic survey on Farm Portions 1 and 2 of Rooderand Farm. The farms were surveyed on lines nominally 50m apart in an E-W direction. The results of ground magnetic survey will aid in the recognition of sub-surface faults and dykes associated with the Pilanesberg Alkaline Complex and will therefore aid in the planning of the drill holes.

Trenching

A number of trenches are planned to be excavated, these will be designed to provide an more detail on the geology of the RLS on the Rooderand Project area. Wherever the UG2 Chromite Layer, Merensky Reef etc are exposed in the trenches they will be mapped and sampled. A number of trenches will also be excavated to provide PLA with some indication of the width, contacts and dip of the contacts between the late-stage dykes associated with the PAC and the RLS.

Feasibility Studies

PLA plan to complee a Pre Feasibility Study (“PFS”) on the project in the December Quarter 2010. Assuming that the outcome of the PFS is positive PLA anticipates that a Definitive Feasibility will be completed on the project in the June Quarter 2011.