Geology of Victoria - Neoproterozoic To Early Carboniferous - Moyston Fault

Moyston Fault

The Moyston Fault is the most important fault as it forms the terrane boundary between the Delamerian and Lachlan fold belts. These twofold belts show important differences. The Delamerian Fold Belt is mainly composed of Neoproterozoic-Cambrian rocks and was deformed in the Late Cambrian Delamerian Orogeny whereas the Lachlan Fold Belt contains mainly Cambrian-Devonian rocks with the main deformations occurring in the late Ordovician to early Carboniferous interval. The first regional deformation to affect the Lachlan Fold Belt was the Benambran Orogeny, about 450 MYA, after the Delamerian Orogeny. Granites comprise 20% of the total exposed area of the Lachlan Fold Belt and fall within an age range of 440 to 350 MYA. Volcanics associated with the granites are also widespread and cover an additional 5%. Blocks of older crust consisting of Neoproterozoic-Cambrian rocks, such as the Selwyn Block in central Victoria, were deformed during the late Cambrian Tyennan Orogeny prior to being incorporated into the Lachlan Fold Belt.