Results of prospecting operations in the Ringwood area, NT.

Abstract

1. During the period December, 1966 to June, 1967, geological mapping, geochemical stream sediment and rock sampling, induced polarization and magnetic geophysics and finally a rotary percussion drilling programme were completed within the companies Authorities to Prospect No 1584, 1585, 1691, 1714 and 1716 of 502 square miles located in the Ringwood - Limbla area east of Alice Springs

2. The geology of the area consists of Archaean Arunta Complex rocks unconformably overlain by the Upper Proterozoic, Heavitree Quartzite, Bitter Springs Limestone Areyonga and Pertatataka Formations and Cambrian Pertaoorrta. Group. These rocks have been folded along north and north trending axes to yield a type of Basin and dome, structure complicated by later faulting along similar north and north directions

3. Bedded base metal mineralization has been discovered in five different stratigraphic horizons from the top of the Bitter Springs Limestone to the Waldo Pedlar member of the Pertatataka formation

4. After attempting stream sediment geochemistry which was unsuccessful, prospecting methods have been to follow out stratigraphic zones containing known mineralization and teat them in favourable areas by means of geological mapping, rock sampling geochemistry, and geophysics along reconnaissance lines; finally drilling the most interesting

5. In the Line E area results of this work have disclosed a 100 foot thick zone of grey dolomitic siltstones of the Ringwood Member which carry lead and zinc mineralization The best intersection checked by chemical assays yielded 0.38% Pb over a true thickness of 25 feet. As the whole sequence does not outcrop on the surface, gives a definite low order IP anomaly, and is open both down dip and to the west and south it still has considerably potential

6. In the Line X area disseminated bornite and chalcocite mineralization in a zone up to 16 feet thick and 3000 feet along strike is associated with grey dolomites of the Bitter Springs limestone directly overlying intermediate volcanics. However, drilling here has shown that the mineralized grey dolomite intertongues with barren red argillites both down dip and along strike so that the beds never reach economic proportions

7. In the Line L-M Area a high order IP anomaly, occurring in the Areyonga Formation, tested by drilling was shown to be associated with carbonaceous pyritic shale of no economic importance

8. In the Line G Area a low order I anomaly and minor malachite mineralization lies in the same stratigraphic position as the Line X mineralization Unfortunately two holes failed to penetrate the zones of interest

9. In the A-D Area high geochemical values and possibly low order IP anomalies were associated with grey dolomite interbedded with red shales at the top of the Ringwood Member. However the grey mineralized beds were considered to be too narrow and widely apart to form an economic thickness

10. On Line P two low order IP anomalies do not appear to be of any major interest

11. Lines H, N, R, T and D disclosed nothing of interest

12. Therefore the only area where additional work is warranted is in the Line E area where such work is recommended