Are gold deposits in the crust fractals? A study of gold mines in the Zimbabwe craton

Geological Society Special Publication - Tập 155 Số 1 - Trang 141-151 - 1999
Tom Blenkinsop1, David J. Sanderson2,3
1Department of Geology, University of Zimbabwe, PO Box MP167, Mount Pleasant, Harare, Zimbabwe
2Department of Geology, University of Southampton, Southampton Oceanography Centre, Southampton, SO14 3ZH, UK
3T. H. Huxley School of Environment, Earth Sciences of Engineering, Royal School of Mines, Imperial College of Science, Technology and Medicine London SW7 2BP, UK

Tóm tắt

Abstract The hypothesis that gold deposits in the earth are fractal dusts is tested using data on gold mine distribution in the Zimbabwe craton. Mine distribution reflects deposit distribution only indirectly because of undiscovered deposits and economic factors. Nevertheless, box counting shows an approximately linear relationship between the logarithm of the number of squares necessary to cover all mines in the craton and the logarithm of the square size between 10 and 60 km, indicating a fractal distribution. More detailed data from two areas within the craton have a similar relationship between square sizes of 2.5–20 km. Departure from the ideal fractal relationship is termed ‘roll-off’, and is very satisfactorily modelled by random sampling of a fractal dust. The results are consistent with the hypothesis that gold deposits are fractal dusts with fractal dimensions of c. 1.0 and the distribution of mines can be regarded as a random sample of the distribution of deposits. Making this assumption, regions that have been incompletely but randomly explored can be identified and distinguished from regions containing large subareas that have been completely unexplored, and appropriate exploration strategies can be devised in either case.

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Tài liệu tham khảo

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Geological Society Special Publication

Tập 155 Số 1

141-151

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