The geology of the Grow West area is significant. Shaped by volcanic activity, fault movements, and sea level changes (Rosengren, 1986)[1], these forces created features like lava flows, deep gorges, and glacial deposits.

Around 400–500 million years ago, the area was underwater, allowing sand and mud to settle. When the sea retreated, mountains formed and were later eroded. About 250 million years ago, glaciers exposed granite and left behind rubble, sandstone, and some of the world’s oldest glacial deposits (Lubczenko, 1994)[2].

Roughly 1–2 million years ago, fault movements formed deep gorges along local rivers. More recent features include river and slope deposits, sandy fans near fault lines, and terraces in river valleys (Rosengren, 1986)[1]; (NRE Flora & Fauna Port Phillip Region, 2002)[3].

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[1] Rosengren, N. J. (1986)
Sites of Geological and Geomorphological Significance in the Western Region of Melbourne.
Prepared by the Department of Geography, University of Melbourne for the Department of Conservation, Forests and Lands, Victoria.
[2] Lubczenko, V. (1994)
From Land Despair to Landcare. ‘Reading the Land’ around Bacchus Marsh.
Department of Conservation and Natural Resources Victoria and the Geography Teachers’ Association of Victoria.
[3] NRE Flora & Fauna Port Phillip Region (2002)
A Strategy for conserving biodiversity in the Central Victorian