Australia: The Land Where Time Began

A biography of the Australian continent 

Australian Glaciation - Carboniferous glaciations

It is believed there were at least 2 glacial periods in Australia, the first being during the Early Carboniferous, that possibly extended to the start of the Late Carboniferous. Evidence for this glaciation is found in the redeposited clasts in the New England area, northeastern New South Wales. These are believed to have resulted from montane glaciation associated with the uplift of the alpine chain. The next evidence for glaciation in Australia is found in many areas from the beginning of the Permian, the Asselian, possibly extending to the beginning of the next stage, the Sakmarian. Evidence for a number of major fluctuations in the Asselian have been found in Western Australia. The glaciation appears to have receded at the time of the global eustatic sealevel rise early in the Tastubian (the lower part of the Sakmarian). There is no known definite evidence of glaciation in Australia, or elsewhere, in the Permian. Evidence for the type of climate that prevailed in Australia for the period between the 2 glacial episodes, but evidence from South America and elsewhere suggests it may have been a warm period. Most evidence for the glaciation is in the form of debris deposited in the developing sedimentary basins of the time, and is of a wet-based type. It appears glaciers were active on the high country, but there is no evidence to indicate how far glaciers spread over low-lying areas. It is not known if a thick, Antarctic-type, ice sheet was present, but there is no known evidence suggesting it may have been.

A number of major climatic fluctuations occurred during the remainder of the Permian, at times there would have been seasonal ice and possibly including icebergs during the coldest periods (White, 1994).

The most widely represented of the older glacial periods occurred during the Late Palaeozoic or Permian. Ice sheets covered most of south and southeastern Australia for about 120 million years from about 280 Ma. In the east of the continent there was widespread volcanicity, and of the rest of the continent, there are suggested to have been glaciers in some places, and probably periglacial conditions over much of the remainder (Twidale & Campbell, 2005).

Evidence of this glacial event can be seen in the glaciated pavements of the Inman Valley, South Australia, Bacchus Marsh, Victoria, and in eastern New South Wales. On top of Black Cliff, Hallett Cove, several kilometres to the south of Adelaide, there is a glaciated pavement with associated erratics. It, and the glacial or fluvioglacial strata that were exposed in the adjacent amphitheater, were found by W. Howchin to be overlain by a thin fossiliferous layer of marine limestone from the Pliocene. The striated pavement was exhumed from beneath glaciogene (deposited by melting ice) and marine beds.

At Black Cliff the deposits and forms are older than the Pliocene. The rocks the pavement is eroded in are of Precambrian age, and the glaciogene strata are above it. Evidence for large time scale multiglaciation, in the form of an erratic from the Sturtian glacial deposits exposed to the east is present on the black Cliff pavement, and there are other erratics of various granites of Early Palaeozoic age from areas to the southeast. At Cape Jervis, a few kilometres south of Hallett Cove, foraminifera were found in marine facies, interbedded with glaciogene strata, that were determined to be cold-water forms. This discovery confirmed that the pavement and glaciogene strata, that are of pre-Pliocene to post-Early Palaeozoic age, were of Permian age, allowing them to be correlated with the occurrences from the Late Palaeozoic of Victoria that had been stratigraphically determined.

A back marker for landscape development over wide areas of the Australian continent has been provided by glaciation of southern Australia during the Permian, the ice sheets having erased evidence of earlier landscapes, the only pre-glacial formations that are presently known from the areas that had been glaciated, such as the glaciated pavements, have been exhumed by weathering and erosion since the melting of the vast ice sheets (Twidale & Campbell, 2005).

  1. Neoproterozoic Australia
  2. Kimberly Region, Western Australia, Glaciation in the Late Neoproterozoic - an 17O

 

Sources & Further reading

  1. Mary E White, After the Greening, The Browning of Australia, Kangaroo Press, 1994
  2. Twidale, C.R. & Campbell, E.M., 2005, Australian Landforms: Understanding a Low, Flat, Arid, and Old Landscape, Rosenberg Publishing Pty Ltd.

Links

Author: M. H. Monroe
Email:  admin@austhrutime.com
Last updated 02/07/2013

 

Aridification of Australia
Glacial Maximum
Ice  Ages
Ice Age Biotas
Pleistocene Ice Age
Precambrian Glaciation
Climate cycles in a Cooling Australia
Sturt glaciation
Marinoan glaciation
Home
Journey Back Through Time
Geology
Biology
     Fauna
     Flora
Climate
Hydrology
Environment
Experience Australia
Aboriginal Australia
National Parks
Photo Galleries
Site Map
                                                                                           Author: M.H.Monroe  Email: admin@austhrutime.com     Sources & Further reading