Carrapateena is an underground sublevel cave operation. To maximise future value from the Carrapateena copper–gold resource, an expansion study has been completed to feasibility study level to assess a larger block cave expansion below the current sublevel cave. This paper will summarise Carrapateena block cave mine design and planning from pre-feasibility to feasibility study.

Geochemical techniques played a major role in exploration of the Tonkin Springs district and ultimately led to discovery of economically significant bodies of gold mineralization. Using some of the information obtained during the exploration program, it is possible to review the geochemical environment, secondary dispersion processes and survey techniques used successfully in this part of Nevada.

The Tonkin Springs district is located in west-central Eureka County, Nevada, within the Simpson Park Range approximately 65 km northwest of the town of Eureka (Figure 7.1). Topography is typical of the Basin and Range structural province being characterized by long narrow valleys and north easterly trending mountain ranges with elevations varying between 1,700 and 3,100 m. Precipitation is in the order of 400 mm per year, the major portion of which occurs in the higher elevations during winter and spring. Soils are light brown to brown desert soils of residual origin in locations above the gravel-filled valleys and pediments. Vegetation consists of sagebrush and sparse grass in the valleys with juniper, pinyon and mountain mahogany in the higher country.

Electrical well logging was introduced to the oil industry over a half century ago. The first log was recorded on September 5, 1927, in a well in the small oil field of Pechelbronn, in Alsace, a province of northeastern France. This log, a single graph of the electrical resistivity of the rock formations cut by the borehole, was recorded by the “station” method. The downhole tool (called a sonde) was stopped at periodic intervals in the borehole, measurementsw ere made, and the calculated resistivity was hand-plotted on a graph. This procedure was repeated from station to station until the entire log was recorded.<...>

I discovered the existence of the Ankarana in 1981 when I was a geology student at Nice University attending the lessons of Prof. Julian, a famous French karstologist, along with three comrades who were also cavers. One day he showed us a map from a book based on work that had been carried out in the north of Madagascar: The Ankarana Plateau by Georges Rossi (1980). At first glance we were fascinated by the landscape represented on the map. Reading the book, an important part of which was devoted to the karst areas of Red Island (Madagascar), was the incentive we needed for us to put on on our cavers’ boots and explore such a remote area. <...>