The kimberlite pipes and fissures which occur on the Paardeberg East property were intruded into Karoo Supergroup sediments. Within the project area are six potential targets: proven kimberlites (PK) PK1, PK2, PK3 (including PK3 central and PK3 east), and prospective kimberlites (P) P4, P5, and P6. Kimberlites PK1, PK2, and PK3 are known to be diamondiferous, but very little is known about anomalies P4, P5 and P6.
The future path for Paardeberg East can be summarized as:
- Bulk sampling and determining the economics of PK1 and PK3;
- Exploring the targets on the remainder of the farm and its surrounding areas; and
- Using the DMS facility to sample additional kimberlite exploration targets in the Company's portfolio.
Project Location
The property under consideration comprises Portions 10, 11, 12, 13, 14, 16 and 17 of the farm Paardeberg East 153, covering 5,433.25 ha in total area. Paardeberg East is located 58 kilometres west of Kimberley in the Northern Cape Province of South Africa. PK1 was previously mined by Mazal Mining & Exploration (Proprietary) Limited (MME) and some mining infrastructure remains on the property. The remaining infrastructure consists of a plant; slimes dam; a number of buildings, including a sort house, offices and workshops; and a waste dump. Since acquiring the property, BRC DiamondCore has erected prefabricated offices and accommodation facilities on site.
Historical Exploration and Mining
Exploration and limited mining activities on the Paardeberg East property date back to the early 1900s. The three known kimberlite bodies, PK1, PK2 and PK3, have all been worked to a greater or lesser extent. De Beers undertook exploration of the property in the late 1980s. An airborne magnetic survey was undertaken in 1988 and 1989, identifying six magnetic anomalies on the property. Three of the anomalies were found to be the known kimberlites, PK1, PK2 and PK3 central. The other three targets, P4, P5 and P6, were not explained. De Beers drilled several holes on PK1 and PK3 central. A full report on De Beers' activities is not available to BRC DiamondCore.
MME began trial mining activities on PK1 in May 1998. Its recorded production was 2 939.24 cts at an estimated grade of 10.75 cpht. Mining stopped in 2002. In addition, two bulk samples totalling 4 740 t were taken between August 2000 and January 2001.These yielded 506.67 cts, which gave an average grade of 10.69 carats per hundred tonnes (cpht) supporting the production grade estimate.
In 2003, geological consultants, Geoventures, reassessed the existing data and produced a computerised model for the PK1 kimberlite. Four boreholes were drilled to address specific issues that could have a material influence on the estimated volumes/ tonnages of kimberlite present. Also in 2003, consulting firms MPH Consulting South Africa Pty Ltd (MPH) and SRK Consulting (South Africa) Pty Ltd (SRK) produced 3-D computer models and block models for PK1, using the surveyed boreholes and recent mapping. This data, and more pit mapping, have subsequently been entered into Datamine, and various block models have been reconstructed.
 Figure 2: Conceptual open pit design for PK1 kimberlite in orange and the existing pit in blue |
Legal Aspects and Tenure
BRC DiamondCore owns both the surface and mineral rights (Old Order Rights to Private Minerals) over Paardeberg East 153. Surface rights are held over the area surrounding the PK1 and PK2 kimberlite bodies. A Mining License (ML 1/1999) to mine for diamonds is currently valid over Portions 10,11,12,13,14,16 and 17 of Paardeberg East 153. The Mining License is valid until 2009, at which time a conversion will be required to a new order mining right.
Project Update
Site and infrastructure preparation for the bulk sampling programme has been completed. The objective is to commission this project within six months via a regional bulk sampling/ trial mining facility. The facility will also be utilised as a central point for the regional kimberlite exploration.
As previously discussed, the Company has acquired a 50 tph DMS module from the Simolotse Mine. After the plant arrives on site it will be adjusted to meet the requirements of the sampling programme.The appropriate sized crushers, scrubber unit and final recovery unit will be purchased.
Hatch has completed the design and final dimensions for a safe working pit at the PK1 site and the pit perimeter has been demarcated by a mine surveyor. ITASCA Africa (Proprietory) Ltd (ITASCA) has completed a report regarding the rock mechanics and slope stability requirements, and these requirements have been integrated into the Hatch design for the safe working pit.
Following the making safe and other excavation work at the PK1 deposit early in the year, a bulk sampling programme initially consisting of twelve bulk samples at PK1 totalling 70,000t, three bulk samples at PK2 totalling 15,000t and five bulk samples at PK3 totalling 32,000t are being processed at present. Processing of these bulk samples through the primary, secondary and tertiary crushing plant with a 50tph DMS plant began in July. In addition to the processing of this bulk sample material, approximately 240,000t of tailings and stockpiled kimberlite material will be processed. Diamond Core expects to complete a review of the initial sample results by year-end 2007.
The strategy for the Paardeberg East kimberlites will be to establish the grade and diamond value of each target in order to optimise a mining plant for the Paardeberg East kimberlites. Some rehabilitation work on damaged areas and unused open trenches has also been planned, in conjunction with the waste stripping. Calcrete from the overburden stripping is being used to strengthen the slimes dam in accordance with a plan by the CDM Group.
