Evolution of Australian Biota done by George
Construct a timeline that identifies the key events in the formation of Australia as an island continent from its origins as part of Gondwana:
mya = million years ago scale=1 cm:10 mya
2. Illustrate the direction of movement and position of continents over time by constructing a series of diagrams of the continents that formed from Gondwana. For each set of diagrams include how many millions of years ago each position occurred: Mio = million
3. Describe evidence of the changing environmental conditions on the Australian continent as a result of this movement. Triassic period (200-250mya): During this period Australia was connected to the other countries that make up Gondwana and as a result they all shared similar climates. Australia was near the equator so it was hot and dry with infrequent rains. Some parts of Australia were flooded as sea water levels increased because of the absence of polar ice caps. Jurassic period (200-145mya): During this period Australia was drifting south of the equator and had a warm and wet climate which had cooled down as a result of drifting away from the equator and made way for plant life to flourish. The dry plains of the north and west now accumulated shale, limestone and sedimentary rocks due to a decrease in Australia’s temperature. Cretaceous period (144-65mya): During this period Australia separated from Gondwana but was still attached to Antarctica and was drifting south rapidly. North Australia experienced warm weather and South Australia experienced cool weather. Tasmania became covered by water due to sea levels rising and ice caps formed in Antarctica, Evidence of this can be found through the carbon dating of ice caps that can be dated back to the cretaceous period. Quaternary period (2.5mya-present): During this period Australia is isolated from other continents and has a hot and dry climate which...
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