International Prospect Ventures Announces Agreement to Acquire 50% Interest in 8 Properties in the Pilbara Craton, Western Australia - Seite 2

The Witwatersrand Basin

The primary gold-bearing clastic sedimentary rocks that make up the gold deposits of the Late Archaean Witwatersrand Basin, referred to as conglomerate, were deposited in ancient rivers, streams and oceans. Subsequent physical and chemical processes over time, introduced gold into the "reefs" that are mined in South Africa. Although there is still no consensus on how and when the Witwatersrand gold deposits formed, most geologists who have studied the Witwatersrand Basin are persuaded by the strong sedimentological controls on gold distribution and so favour palaeoplacer models for gold deposition. More than 1.6 billion ounces of gold have been mined from the conglomerate beds (gold reefs) of the Witwatersrand Basin.

The Hamersley Basin and Fortescue Group

The Late Archaean-Palaeoproterozoic Hamersley Basin and related sub-basins formed on an older granite-greenstone basement (Pilbara Craton) during the initial stages of Late Archaean continental rifting. The Fortescue Group, which ranges in age from 2.8 to 2.6 billion years, unconformably overlies the granite-greenstones of the Pilbara Craton and is commonly compared to the Ventersdorp Supergroup of the Witwatersrand Basin in South Africa. Gold-bearing conglomerates have been identified by Novo Resources Corp. at several stratigraphic levels in the Fortescue Group (e.g., within the Nullagine sub-basin). Similarities between palaeoplacer deposits hosted by conglomerates in the Fortescue Group and the gold-bearing reefs mined in South Africa have been recognized for over a century.

The Nullagine Sub-basin

The Nullagine sub-basin formed on an older granite-greenstone basement during the initial stages of Late Archaean continental rifting and formation of the more extensive Hamersley Basin. Alluvial gold was first discovered in the Nullagine sub-basin in 1886 and by 1893 the Nullagine region had become a major gold field. A hard-rock source for alluvial gold deposits at Nullagine was identified in 1895. In recent years, gold-bearing conglomerates have been identified at several stratigraphic levels in the Fortescue Group within the Nullagine sub-basin, including the recent work by Novo Resources.