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Lake Bullen Merri and Lake Gnotuk

Location

CAMPERDOWN VIC 3260 - Property No L10270

File Number

L10270

Level

National

Statement of Significance

File note 31/05/2012: Now incorporates L10285 (Lake Bullen Merri / Lake Gnotuk Advisory Committee), and L10292 (Lake Gnotuk).

Lake Bullen Merri is a maar, a broad volcanic crater formed by one or more major volcanic explosions during the late Tertiary period. Much of the ash and scoria ejected during the explosions fell nearby to create a raised rim around the crater. Within the crater, water has accumulated to form a brackish lake. Around the lake the native vegetation has almost all been cleared and replaced with pasture grasses, though some replanting of native species is now occurring. Lake Bullen Merri is significant for scientific reasons at the International level, and for its aesthetic qualities at the National level.

Lake Bullen Merri is a good example of a lake within volcanic maar, a crater formed by violent volcanic explosions, and the landform is classified by the Geological Society of Australia as of National Significance.
Study of the sediments which have accumulated on the floor of Lake Bullen Merri has contributed much to the understanding of climate change across the Quartenary period in southeastern Australia
Lake Bullen Merri supports an important population of indigenous fish species, notably Galxids (Glaxis maculaturs) and Gudgeon (Philypnodon grandiceps) The galaxids are a unique population because these fish normally migrate to breed, but due to the landlocked nature of the lake have here evolved in isolation
Lake Bullen Merri is a striking blue lake in a deep hollow, with an attractive pastoral landscape on the ridge enclosing the lake. It remains full of water all year, so is a particularly valuable feature of the inland of the state during dry summer months.
Classified: 10/11/2003

L10292 (Lake Gnotuk)
What is significant?
Lake Gnotuk is a maar, a broad volcanic crater, bordered by a high steep rim formed by deposition of scoria (fragmented lava) and ash ejected during the eruptions. A hypersaline lake has formed within the crater.

The slopes around the east, north and west sides of Lake Gnotuk are grassed, with an almost intact pastoral landscape. On the south side, on the ridge between Lake Gnotuk and Lake Bullenmerri, there is a recreation area with a golf course, camp ground and botanic garden.

How is it significant?
Lake Gnotuk is significant for scientific reasons at the International level, and for its aesthetic qualities at the State level.

Why is it significant?
Lake Gnotuk is listed as one of the 25 geological features of International Significance in the State (RPD Group, 2001, p.4). It is described as of importance for representation of landform type, outstanding nature, and as a geological monument, important for education, research, reference and recreation/aesthetic aspects (Joyce and King, 1980, p.37).

Sediment which has accumulated on the floor of Lake Gnotuk has been extensively analysed to yield a detailed record of vegetation and climate change in the immediate area over the at least the past ten thousand years.

The combination of a wholly enclosed, often blue lake, which emerges as a surprise to the viewer who climbs the bordering ridge, and the steep grassy hill backdrop, provides a visually pleasing feature in the rather flat lava plain of the Western District. It is an important component of the local tourist group's concept of "Lakes and Craters Country", listed in the Volcanoes Discovery Trail for motorists and a major feature of the proposed Kanawinka Geopark.
Classified: 26/7/2008

Group