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Australia: The Land Where Time Began |
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Cradle Mountain Continental crustal extension between Australia and Antarctica in the Jurassic resulted in the emplacement of vast amounts of molten rock beneath Tasmania, estimated to be about 5000 cubic kilometres. Areas of crustal weakness were caused by detachment faults meeting the aesthenosphere in the region. Cooling molten magma rising beneath the land surface became dolerite. The land surfaces previously covering this dolerite has been removed by erosion in many places, exposing many of Tasmania's dramatic features, for example, Cradle Mountain, being composed of the volcanic rocks that resulted from the breakup of Gondwana. It was the first time Australia had separated from Antarctica for about a billion years.
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Author: M.H.Monroe Email: admin@austhrutime.com Sources & Further reading |