Cooke Report 29 October 1998

Page 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8

Page 2/8

INTRODUCTION
This report covers an evaluation of the diamond potential of the Muirton Project, situated on the farm Muirton (click to see location plan) which lies on the west bank of the Vaal River between Schmidtsdrift and Delportshoop, Northern Cape Province. The study was requested by Mr Carlos Aranjo of Regal Royal Developments (Pty) Limited and is based on a review of all prospecting and mining data and two site visits on 28 May and 29 September 1998.
GEOLOGY

Alluvial diamonds are found in gravel deposits associated with the ancient Vaal River drainage system. The gravels in this general area have been deposited on bedrock comprising andesitic lava of the Allanridge Formation (age about 2 600 million years), sedimentary beds comprising quartzite, dolomite, limestone and shale of the Black Reef and Schmidtsdrift Formations (age about 2 300 to 2 500 million years) and shales and tillite of the Dwyka Formation (age about 350 million years). In the Muirton area the bedrock consists mainly of shales of the Dwyka Formation.

Valleys coinciding with the present Vaal and Orange Rivers were formed by glaciers during Pre-Karoo times. Alluvial diamonds were subsequently deposited along these valleys during the Quaternary Period (age about 1 million years) when diamonds, eroded from kimberlite pipes and fissures, were transported by the ancient Vaal River drainage system.

At Muirton alluvial diamonds are associated with:

A palaeo channel (Deep Structure) formed in an ancient river channel. Exceptionally high-grade gravels are usually found in the deeper sections of such channels.
Terrace Deposits occurring on the flanks of ancient or recent river valleys. These are formed when the river finds a temporary base level. The thickness of the gravel varies widely from a single layer of pebbles to deposits filling major irregularities in the floor. The gravels consist mainly or large boulders or lava (Allanridge Formation) quartzite, and dolerite in a fine matrix of small pebbles and sand. Most or the gravels have been calcretized to varying degrees and clay is present in places.
Channel deposits in the present Vaal River which has a total length of 2 km on the Muirton property. gravels are generally round in the deeper parts of the river and may be very rich locally. Areas of enrichment are usually associated with alluvial traps such as bedrock irregularities, rock bars, plunge pools and the presence or large boulders. These unstratified gravel deposits consist of well-rounded, compact boulders and pebbles of Ventersdorp (Allanridge Formation) lava, quartzite, silicified shale and agate set in a matrix of fine- to medium-grained river sand. These deposits on Muirton have been mined in the past. However, diamonds tend to be moved during floods and re-deposited in favourable alluvial traps. These areas could then be re-examined for diamond recovery.

Page 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8