East‐directed overthrusting in the Melbourne Zone, Lachlan Fold Belt

Abstract

Inclined northeast‐vergent asymmetric regional F1 folds cut by thrust faults characterize a fold‐to‐fault transition into the Mt Wellington Fault Zone on the eastern margin of the Melbourne Zone of central Victoria. In the most southerly exposed part of the Mt Wellington Fault Zone at Lake Glenmaggie, polydeformed interbedded sandstone and mudstone of Silurian(?) age are unconformably overlain by weakly deformed Late Devonian conglomerate and volcanic rocks. Three deformations pre‐date the Late Devonian succession, which has itself been warped into a series of open folds. Thrusting (D1) along southwest dipping reverse faults and thrusts produced imbrication and juxtaposition of different lithological groups. Fault slices of strongly cleaved, interbedded sandstone and mudstone abut against a weakly deformed mudstone‐siltstone sequence, thereby suggesting significant displacement on some of these faults. Thrust sheets consisting of large panels of overturned homoclinally dipping strata represent the faulted...