Australian landscapes are ancient, the heady days when rift valleys tore Gondwana apart, and sea floor spreading propelled its fragments around the globe are long gone. It’s hard to imagine a Mt Nyrigongo popping up and obliterating Adelaide. And I do so miss her warmth, the twinkle in her magma and her sweet sulphurous perfume.
But the reality is that western Victoria is littered with volcanoes. It’s just the timing that’s out of kilter.
Ken Grimes, of the Hamilton Field Naturalists Club has written a very nice paper on the subject which you can find <HERE>.
In the Western District there are mainly three types of volcano, though combinations of these also occur. About half of the volcanoes are small steep-sided scoria cones built from frothy lava fragments thrown up by lava fountains. Most of the remainder are broader but flatter lava volcanoes formed from relatively gentle flows of lava welling out of a central crater. A group of about 40 maar cratersnear the coast formed from shallow steam-driven explosions which produced broad craters with low rims. These now often contain lakes.
… no panic is needed. It probably would be a small discharge and a temporary nuisance, rather than the large eruptions we see in the Pacific ‘Rim of Fire’.
explosions crush the overlying rocks and launch them into the air along with steam, water, ash and magmatic material. The materials usually travel straight up into the air and fall back to Earth to form the tephra deposits that surround the crater.
So there you have it … photographic evidence of life on maars.