A geological report of part of the Para Fault Block

Abstract

A geological outline of the Para Fault Block from a little south of Modbury to the Little Para River.

The author wishes to acknowledge the help and encouragement given by Professor Sir Douglas Mawson and other members of the staff of the Geology Department.

The area investigated is situated a few miles northeast of Adelaide. Its eastern and western limits are marked by two well defined fault scarps which are sub parallel. The western fault is known as the Para and the eastern as the Eden Fault. The southern boundary has been taken as the Grand Junction Road owing to absence of outcrops south of this line. The northern boundary has been fixed at the Little Para River owing to pressure of time. There is some suggestion that the geology north of this boundary is essentially similar to the area under discussion.

Some investigation was carried out east of the Eden Fault. This was made as an attempt to determine the position of the Block in the generally accepted sequence known as the Adelaide System. No very detailed mapping was carried out. Little more than a log of beds above the schists of the Barrossian Complex was prepared.

These investigations proved of little benefit as faulting has greatly disturbed the sequence. As yet no displacement can be measured as location of marker beds is not definite.

Owing to relatively flat topography of the Block there is little removal of eroded material and hence rock exposures are poor except adjacent to the creeks.

Investigation has been confined to field mapping. Air photos proved useful only as a means of location. The photos showed no geology except for some trend lines adjacent to the Little Para River.