More than 420 million oz of gold were concentrated in circum-Pacific synorogenic quartz lodes mainly during two periods of continental growth, one along the Gondwanan margin in the Palaeozoic and the other in the northern Pacific basin between 170 and 50 Ma. These ores have many features in common and can be grouped into a single type of lode gold deposit widespread throughout clastic sedimentary-rock dominant terranes. The auriferous veins contain only a few percent sulphide minerals, have gold:silver ratios typically greater than 1:1, show a distinct association with medium grade metamorphic rocks, and may be associated with large-scale fault zones. Ore fluids are consistently of low salinity and are CO2-rich.

In the early and middle Palaeozoic in the southern Pacific basin, a single immense turbidite sequence was added to the eastern margin of Gondwanaland. Deformation of these rocks in southeastern Australia was accompanied by deposition of at least 80 million oz of gold in the Victorian sector of the Lachlan fold belt mainly during the Middle and Late Devonian.
Lesser Devonian gold accumulations characterized the more northerly parts of the Gondwanan margin within the Hodgkinson–Broken River and Thomson fold belts. Additional lodes were emplaced in this flyschoid sequence in Devonian or earlier Palaeozoic times in what is now the Buller terrane, Westland, New Zealand. Minor post-Devonian growth of Gondwanaland included terrane collision and formation of gold-bearing veins in the Permian in Australia’s New England
fold belt and in the Jurassic-Early Cretaceous in New Zealand’s Otago schists.

Post a Comment

Don Ellwood said... August 2, 2014 at 7:58 AM

This map is useless without notes.

OutdoorSpirits! said... August 2, 2014 at 8:39 AM

Don Ellwood states, "This map is useless without notes.", I disagree Don, as it narrows down the geological timeline especially for myself, *In the write-up considering the Macro Layout, "northern Pacific basin between 170 and 50 Ma". Possibly to confirm looking in the area *focusing - between 65-50Ma in regards to the geological rock ages, in metamorphic well faulted zones. As well as, other key points I figure are worth something - Ore fluids are consistently of low salinity and are CO2-rich, to include, "Victorian sector of the Lachlan fold belt mainly during the Middle and Late Devonian" - Hence, "the Welcome Stranger was found at Moliagul, Victoria, Australia in 1869 by John Deason and Richard Oates. It weighed gross, over 2,520 troy ounces (173 lb) and returned over 2,284 troy ounces (156.6 lb) net" cite- http://en.wikipedia.org/wiki/Welcome_Stranger , not exactly sure at this moment Moliagul, Victoria, Australia falls within this belt but if what I do know Victoria Sector = Victoria Territory *Australia