between Bacchus Marsh and Ballan, this park was established in 1910 to protect its geologic significance with its exposed uplifted and folded Ordovician seabed.
the fine blue-grey clay mixed with pebbles in the cliff walls called tillite formed from sedimentation of ancient ice sheets in the Permian glaciation 280 million years ago.
parallel scratch marks on cliff rocks are evidence of ice moving in glaciers during the ice age.
parts of the cliffs have vertically oriented shale deposits which are marine sediments tipped on their end by tectonic movement which lifted them above sea level some 350 million years ago.
today it is a relatively easy flat bush walk along a small river with an option to make it a 5hr circuit through more bushy terrain - just watch out you don't step on one of the extremely venomous snakes found all over Australia, especially along gullies such as these (although all I saw in 3hrs is a harmless echidna), and bring walking shoes, hat & water as it can get hot, exposed and isolated in summer.
mind you, not many of the local Melbournians have bothered to come to either of these gorges - but they do make a nice walk in the bush if you come prepared and a chance to cool off in the river on one of the sandy beaches if you are so inclined - a fairly private spot during the week for a skinny dip on a hot day.
for a more energetic walk to stress your heart out, and your ankles, try the nearby Ironbark Gorge track.
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