Mineral Exploration and Development - a Suggested Approach
Bilgrami, S. A., Economic Review
The evolution of the human civilization has been dependent upon the exploitation and utilization of mineral resource. Had we not learnt to exploit mineral resources to our advantage we may still have been living under the trees. The firt industrial revolution commenced when human beings started making use of stone and metal implement. Today minerals have so intimately permeated our lives that we have ceased to feel their presence or our dependence upon them. There is nothing in this roo that does not owe its existence to minerals in one for or another. And yet, how often do we think of the labour, technical skills and financial resources that go into producing finished metals or glass or ceramics which are foundation blocks of human civilization? An ordinary computer uses 18 to 20 metals and an aircraft over a dozen. The multiplying effect of the benefits of using minerals is brought into focus by the following calculation given by Brown (1989). In 1988 American miners produced an estimated US $30 billion worth of raw materials-unprocessed ores, sand, gravel, stone etc., as they came out of the mines. These ores/minerals were used to turn out a total of US $300 billion worth of finished metals, fertilizer, cement, glass, ceramics and other processed materials. These were the essential buildig blocks for all goods and services making up the Gross National Product estimated at US $480 billion. Thus each dollar's worth of mineral mined added 162 dollars to the GNP. Such a contribution is not made by even the most prevalent industry-agriculture, which receives by far the greatest attention of all governments, particularly in the developing countries.
Despite this, mineral raw materials are not viewed as particularly relevant to an advanced technological society and mining of minerals is considered destructive of environment. This in general may explain the lack of consciousness about the true role and importane of mineral sector to national economy. Here I would like to briefly mention a few reasons for the slow rate of mineral exploration and development. Having been associated with the mineral industry of Pakistan for the last forty years, I will naturally, cite examples from my own country to project my thinking on mineral exploration and development work. Some of these remarks may also be applicable to other ECO-SAARC countries.
About 20 years ago Pakistan was considered to be a country of industrial minerals only. However, the discovery of Saindak porphyry copper deposit, application of plate tectonic concepts and reinterpretation of the geology of the country have enable Geological Survey of Pakistan (GSP) and other mineral exploration agencies to identify substantial new potential for metallic minerals in the country. It is now accepted that application of modern geophysical techniques, filtration and correlation of data may lead to discovery or large metallic deposits. We, therefore, need to adopt a conceptual model approach to mineral exploration work. Sillitoe (1978, 19799) and Khan (1985) have proposed a conceptual model approach to mineral exploration, particularly of porphyry type deposits. Similar conceptual approach can be applied to exploration for metallic in mineral deposits formed under different environment and structural domains. The following domains of environments for the formation of metallic deposits have been tentatively defined by Sillitoe (1979) and Khan (1985, 1991).
The Island Arc System
Several manifestations of porphyry type polymetallic deposits have been identified in Chagai Kohistan Island Arc System. Except for Saindak, the others have not been investigated in detail. It is postulated that detailed geophysical and geochemical investigations will reveal several polyetallic deposits of better grade and larger tonnage than at Saindak. Occurrence of several massive and Kurokotype sulphide deposits in Chagai and Kohistan regions has been reported but not investigated. …