This report describes a geophysical survey made in May 1952 and August 1953 at the Silver Valley mine workings, near Inverell, N.S.W. From the workings there is evidence of mineralisation along a well-defined fissure and one ore shoot has already been partly developed. The survey was made in an attempt to locate other ore shoots of sufficient size to warrant mining operations. Self-potential, magnetic and electromagnetic methods were used in the survey. The self-potential method showed a well-defined anomaly on the eastern extension of the fissure, indicating that a small body of sulphides may exist there with its centre about 300 feet east of the known ore shoot. The magnetic and electromagnetic results showed no pronounced anomalies which could be correlated with any defined ore shoot. Recommendations are made as to how the self-potential anomaly could best be tested. These comprise sinking a shaft at the centre of the anomaly, extending an existing adit, or driving a new adit from a point nearer the anomaly.

A mineral assessment of the Tombstone study area was undertaken by the Department of Economic Development in the summer of 1998 at the request of the Department of Renewable Resources. The purpose of the mineral assessment was to produce a mineral potential map, which was to be used to assist with the finalization of the boundaries of the Tombstone Territorial Park. Following an initial compilation, a field program was designed to document known mineral occurrences, test and improve the existing regional mapping, investigate geochemical anomalies, characterize favourable environments for mineralization, sample for lithogeochemistry, and prospect for mineralization. A field program resulted in the discovery of several new mineral occurrences, as well as the discovery of previously unmapped geological formations. Fieldwork was followed by a compilation phase that integrated the new information to the existing geoscientific data. The geology of the study area was subdivided into thirteen geological tracts. A panel of five industry and government experts, familiar with the geology, mineral occurrences and mineral deposit types to be found in the area, was convened in June 1999. Based on the final compilation and their expertise, they produced a relative ranking of all the tracts according to their potential to host mineral deposits, from highest potential to lowest. The highest-ranking tracts are those that include, or are near the Cretaceous intrusions (Tombstone, Mount Brenner and smaller intrusions) and have strong potential for intrusion-hosted (Fort Knox-type, porphyry uranium, skarn) and intrusion-related (skarns, veins, replacement) mineralization. Other tracts demonstrate potential for Wernecke Breccia, shale-hosted nickel sulphide, ultramafic-hosted nickel and listwaenite, Carlin-type, Mississippi Valley-type or replacement lead-zinc, as well as volcanogenic mineralization. A final boundary was adopted in December 2000; it includes land outside of the original study area. This final boundary therefore includes areas that were not assessed in this study. All our wildlife sightings were documented and were included in the subsequent wildlife survey.

A geophysical test survey was made at the Mt. Brown Copper Mine, Karangi, N.S.W in October, 1954. The survey was undertaken by the Bureau of Mineral Resources at the request of the Mt. Brown Copper Mining Company, supported by the New South Wales Department of Mines, to assist in prospecting the leases for additional ore reserves. Reopening and developing the present workings is uneconomical without further prospects. Self-potential, electromagnetic and radioactive methods were used in the survey. The magnetic results show a distinct pattern, but this appears to be unrelated to the known deposit and cannot be interpreted satisfactorily until a regional geological survey of the area has been made. It is recommended that this be done. No self-potential anomalies or electromagnetic indications which could be caused by an ore body, were obtained in the surveyed area. Parts of the area were unsuitable for electromagnetic work because of the effects of electric power lines. The very weak variations observed in the self-potential values are accounted for by small local surface effects. .Random radioactive readings over the area gave no indications of radioactivity above background level.

An area of approximately 32 square miles in the vicinity of Rye Park has been mapped in greater detail than that of previous regional surveys. Three possible tungsten-bearing areas have been delineated as warranting magnetometric and plane-table surveys. An extension of each of these three areas is indicated. Attention is drawn to copper, tin, silver, lead, and zinc mineralisation of the area, and it is considered that there are possibilities of finding payable orebodies containing these metals.