:224 Charles Fennev: 



Beginning near the southern end, north of the River Moorabool, 

 we find the fault represented by a ** bank " or scarp, from 200 to 

 -300 feet high on the western side, geologically distinct from the 

 lower plains to the east. Where the line crosses Sutherland's 

 Creek and the Moorabool River, two very distinct formations (the 

 older basalt and the " thin, persistent limestone band '') are 

 abruptly cut oft', and appear only on the up-throw side of the fault 

 (see Geological Quarter Sheet 19 S.W.). To the south of these 

 points the scarp has not been traced, and apparently disappears. 

 Continuing northwards we find the scarp capped by newer basalt, 

 which reappears 250 feet lower on the down-throw side, partly 

 covered by an apron of alluvium. The cutting off of this volcanic 

 sheet appears to have been quite abrupt. 



Further north we have the high peneplain (1300 feet average) 

 •of folded Ordovician slates to the west, abruptly descending to a 

 volcanic plain (500 feet average), with a characteristic alluvial 

 apron along the base of the scarp. The cutting oft of the Ordo- 

 vician is along an almost straight line, which runs obliquely 

 across the strike; the general height of the scarp face here is 800 

 feet. At the Anakies we find that a resistant granite mass in the 

 let-down block, near the scarp, and a piling up of volcanic material 

 below and on the fault line, has somewhat obliterated the straight- 

 ness of the junction, and has made it possible to carry a road 

 from the lower plains to the top of the ranges on the west. 



Beyond the Anakies, at Anakie Gorge, the low basalt (5-600 feet) 

 •comes abruptly to the edge of the Ordovician slates, which then rise 

 at once to a general level of 1350 feet. From this point on to 

 '* Greystones " (near the top of Quarter Sheet 12 S.E.), the 

 physiographic evidence is excellent; deep gorges score the face of 

 the high resistant scarp, and the streams continue on the lower 

 block, in wandering shallow channels across the alluvial apron, to 

 the basalt plains. 



Further north, the nature of the country alters completely, the 

 fault line turns north-easterly, and then again more northerly 

 through Bacchus Marsh. Newer volcanics mask the scarp, except 

 where exposed in sections. The Parwan and Werribee have cut 

 •deep into the uplifted block and show the geological structure 

 Avest of the fault to be of the complex nature common to the 

 '' Ballan sunkland " (block C). The scarp here is generally lower; 

 basalt in most cases covers the slope, and occurs both upon the 

 \ipper and lower blocks. It is suggested (Fig. 7b) that the basalt 

 sheet must have undergone fracture slowly, and have thus clung 



