The silver-lead-zinc ore is found as thin layers of minerals alternating with bands of hardened mud (shale), whereas the copper ore consists of cross-cutting veinlets of copper minerals within masses of ‘silica dolomite’ Most geologists today agree that the minerals at Mt. Isa were originally deposited at the same time. In addition, it is now commonly recognized that they were deposited by hot underwater metal rich volcanic ‘springs’ like those found today in the Red Sea, Gulf of California and the East Pacific.
Statistical analysis of the metal ores and the sediments they are in, shows that all the silver-lead-zinc ore bodies and their host shales could have been deposited in less than 20 days! Lead isotope data also points to rapid deposition on a massive scale. Such a turbulent underwater volcanic setting for this rapid deposition is reminiscent of the ‘fountains of the deep’ during Noah’s Flood, and the fact that the shales which contain the metal ores are full of fossils, only reinforces this. For further information see the technical article in this issue.