West Coast Range

Tasmanian North West and West Coast Range regional Geology

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Location: TASMANIA

West Coast Range

Post by admin » Tue Aug 20, 2013 7:40 pm

i have not prospected all the West Coast Range. From the Gog Range (both sides) down to the Bird River but not below Maquarie Harbour or the out towards the Tyndalls. (WHA) its ancient ish sea bed that has been uplifted in spectacular fashion after it was hit with a chain of undersea volcano's that precipitated Massive Sulphides on areas of rupture and weakness. The Thrust Faulting and subsequent folding helped create the deposits and the volcanic chain that stretches to the tip of Cape York in QLD. Its the same event at different times. i think. Everything East of the Great dividing range is seabed, as an example. I imagine it was a massive pluton that sat stationary and as our Australasian tectonic plate drifted north and was hit from the East its crust was weakened by the volcano, like tearing paper. And we uplifted when we hit the expanding Pacific plate and crumpled. The over laying conglomerates are in series and strike in regular fashion.

We had a second volcanism event later on. But it tended further west, Zeehan etc.

i know i have the chronology wrong, but thats how i see it.

The main thrust in Tasmania hit around the now South East coast on the continental shelf i would imagine and angled us up towards the North West. The chain of volcano's being the weak spot. From fossils the ages of the later layers can be used to deduce approx ages of deposition. The stratification typical dips at 60 - 70 degree and decrease in the Fossey Trough to closer to 42 degrees or so.

The area hosts many world class deposit and important and rare minerals only found in a very limited number of localities on the planet.

edit (draft) will add as time permits.
http://www.mrt.tas.gov.au/mrtdoc/dominf ... 997_08.pdf

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