Sunday, November 25, 2012

Devonian in Australia

Paleography suggests that at the beginning of the Devonian period Australia was a peninsula of the Gondwana continent and located near the equator. During the period it moved south and although there was no ice cap growing distance from sun caused climatic changes and cooling. The estimated trip of Australia during Devonian is quite significant, from 15 Northern and 15o Southern latitude down to 35o 45o. (Monroe 2011).

There was strong volcanic activity on the coast of Eastern Australia due to tectonic movements (compare the Fire ring today!) but towards the end of Devonian Australia already resembled the modern continent


Deposits
1. Major carbonate deposits
  • SW Australia (Lachlan Fold Belt
  • North Queensland 
  • West Australia (Canning Basin).

2. oolitic limestone New South Wales (Wee Jasper)

3. Thick sediment on bottom of the sea 
  • South Ausralia (Adelaide basin, Gilmourin luonnonkaasu)
  • Melbourne and Bathurst
4. Shallow sea coral reefs

  • New England 
  • North Queensland


Tabberabberan Orogeny


Devonian sandstone in sycline Cape Liptron Australia
Victoria. Dept of Primary Industries
The geomorphology of Eastern Australia was strongly modified during Middle Devonian by the Tabberabberan orogen. It affected a vast region of more than 200.000 km2 and is part of the Lachlan Fold Belt formation. 


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