The Bremer and Palmer Faults

One of the youngest structures in the Mount Lofty Ranges is the Bremer Fault which forms the western boundary of the Monarto block, near Callington. The total vertical displacement on this fault is only about 100m, enough to divert the east flowing drainage (Mount Barker Creek) into south flowing Bremer River. The fault scarp shows very little incision. Apparent displacement on the fault dies to the north and south, although in the south this may reflect partial covering of faults by recent sedimentation.

Perspective view of the Monarto Block, viewed from the SSE. The block is bounded by the Bremer Fault to the west and the Palmer Fault. Image created form the DENR 100 m DEM.

Perspective view of the Monarto Block, viewed from the SSE. The block is bounded by the Bremer Fault to the west and the Palmer Fault. Image created form the DENR 100 m DEM.

 

 

 

Near the southern tip the fault is draped by a series of E-W trending sand-dunes. The crests of the dune systems show offset across the fault, these significance of which depends on how the dunes have formed. Two hypotheses for dune formation at this locality are:

In the former case the offset of the dune crests across the fault can be attributed to fault movement, while in the latter case the offset may simply reflect draping of the dune system across an existing topographic feature.