Volcanic Mountains

Mountains can be formed by folding, faulting and volcanic activity
Volcanic activity takes place around the margins of moving plates
In the past huge lava plains covered considearable areas of Australia
These occured as the continent drifted over hotspots in the mantle
Hot spot volcanoes form in the middle of tectonic plates over source of magma.
Hot spots stay still but tectonic plates keep moving
33 million years ago as Australia drifted northwards splitting from Antratrica, it passed over a large hotspot.
Next 27 million years about 30 volcanoes errupted
Over millions of years this hotspot process forms a chain
This hotspot is now probably at bass strait
Caldera of the tweed volcano is one of the biggest erosion calderas in the world.
it moved over a hotspot 23 million years ago and errupted finishing 20 million years ago it was 2km high
Ash and lava deposited over its outward slop forming a diamete of 100km
After much erosion Mount Warning remains a remnant central plug and a hard range of mountains, McPherson, Tweed, Nightcap and Koonyum
Mount Warning is about 1100 metres heigh and is so far east that it recieves sunlight first in Australia.

	Criado por ioannis_lion mais de 10 anos atrás

Geography Notas sobre Geography Topic Test Notes, criado por ioannis_lion em 02-04-2014.