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The Emily Ann and Maggie Hays nickel deposits are situated approximately 150 km west of the town of Norseman, Western Australia, within the Lake Johnston Greenstone Belt.〔Hill R.E.T, Barnes S.J., Gole M.J., and Dowling S.E., 1990. ''Physical volcanology of komatiites; A field guide to the komatiites of the Norseman-Wiluna Greenstone Belt, Eastern Goldfields Province, Yilgarn Block, Western Australia.'', Geological Society of Australia. ISBN 0-909869-55-3〕 Having been operational since 2001,〔''The Australian Mines Handbook: 2003-2004 Edition'', page: 28〕 Norilsk Nickel suspended mining at Emily Ann and Maggie Hays in early 2009 because of drastically falling nickel prices.〔(Norilsk Nickel Australia ) Norilsk website, accessed: 10 September 2009〕 ==Discovery== The Maggie Hays deposit was first officially discovered in 1996 by LionOre Australia, although it had essentially been found by prospecting in the 1970s by Anaconda Mines (now Minara Resources) and Union Miniere, who had first discovered a nickel geochemical anomaly and drilled the disseminated halo, but missed the lucrative high-grade massive sulfide mineralisation by as little as 3 metres. The recognition of the Maggie Hays orebody by LionOre geologists in the late 1990s was based upon electromagnetic geophysical surveys and deep diamond drilling of conductive anomalies. LionOre geologists credit the discovery to recognition of the electromagnetic response and drilling of the anomaly, however it is widely recognised that the initial discovery was based upon literature research and the fact that in the late 1970s and 1980s Union Miniere/Anaconda relinquished the tenements in a period of unfavorably low nickel prices. Reassessment of the geophysical signature at Maggie Hays indicates that the hangingwall banded iron formation is as conductive as the massive sulfides, and that on this basis, as well as the steep orientation of the massive nickel sulfides, Maggie Hays is essentially blind to discovery. The Emily Ann orebody is situated approximately 1200m north of the Maggie Hays orebody and was drilled first in 1998 after a prolonged and saturated effort to electromagnetically prospect the entire prospective belt. The Emily Ann orebody was unequivocally discovered by geophysical surveying, the result of a flatter orientation of the orebody, the fact it is hosted within conductively dead felsic gneiss, and the depth of the upper parts of the orebody reaching to within 200m of the surface. The Emily Ann discovery was a technical triumph, because it is a mechanically displaced recumbent fold of sheared massive sulfide hosted several hundred metres off the original ultramafic-felsic conact in a position not generally expected to host nickel sulfides. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Emily Ann and Maggie Hays nickel mines」の詳細全文を読む スポンサード リンク
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