King's Table, Annual report, Mineral Claims N243 to N255 Inclusive, Mineral Leases 1421B to 1423B Inclusive, year ending 14 June 1984

Abstract

The report on the King's Table area by Messrs Shields and Orridge, which accompanies this report, delineated a number of areas of pegmatite and areas of possible concealed alluvial and eluvial wash. Further assessment was separated into two halves, the possibility of further pegmatites being discovered under the laterite cover and the possibility of their containing economic quantities of tin or tantalite: the potential volume of wash available from eluvial and alluvial sources. Within the area of the tenements at six locations there are outcrops of pegmatites. In each case these are up to 6 m wide and up to 100 m long though the average dimensions would appear to be 2 m x 40 m. Mineralisation in the pegmatite is often coarse and many quartz rich pegmatites appear to be largely barren with local concentrations of coarse cassiterite and tantalite. In the case of the quartz poor, mica-rich pegmatites the mineralisation is finer and more evenly distributed. The problem therefore relates to the probability of further more mineralised pegmatites occurring under the lateritic cover; 1. The areal proportion of pegmatites occurring in outcropping areas as opposed to the proportion of country rock is important. It is roughly estimated that perhaps 5 percent or less of the outcropping areas are occupied by pegmatites. 2. The regional trend for the King's Table areas would appear to be the approximately N S anticlinal axis proposed in the Shields and Orridge report. As the pegmatites do not appear continuously in the outcropping areas it may be surmised that some form of cross structure limits the distribution of the pegmatites to short N-S trending sections. 3. All but one of the known pegmatite occurances are approximately located an one N-S linear trend slightly to the western side of the area. The other pegmatite lies to the east and may represent a more poorly exposed trend. 4. The limited evidence available suggests that the N-S trends of intermittent pegmatites are not closely spaced. 5. The sum of all the pegmatites presently known will only total a small volume probably with a relatively low overall grade due to the generally sporadic nature of the mineralisation. Taking all these considerations together, the chances of successful exploration would be tied to the discovery of several pegmatites containing high grade cores of mineralisation under the laterite cover. The average narrow widths of the pegmatites would require very close spaced drilling to have any chance of penetrating a pegmatite. Furthermore, the difficulty in determining the structural control on the pegmatites would mean extensive additional drilling to resolve the problem. The number of pegmatites with economic grades appears to be limited and if the mineralisation is coarse grained then estimation would be very difficult and liable to considerable error. Finally, the chance of discovery of pegmatite with high grade cores would appear to be very low. The area is not considered to present a target which is economically attractive to this company. A slow painstaking search by a prospector might produce a small scale success.