222 Charles Fenner : 



Similar boulders, if found to occur generally over this alluviaF 

 area, at such varying depths, would point to the one-time existence- 

 of basalts on the high land to the west of the scarp, where Ordo- 

 vician is now exposed. 



Further south at Anakie Gorge, right bank, decomposed igneous 

 material banks close up against the Ordovician face, with a high 

 angle junction; the volcanic material undoubtedly continues right 

 up to the base of the scarp at this point. (Fig. 7, Sect. 8c.) 



Section d is a section through the scarp at about the locality of 

 O'Neill Bros.' farm, some five miles south from Mt. Anakie, and 

 east of the village of Maude. The higher basalt shows an even, 

 level, lower margin right to the edge of the scarp, and reappears 

 on the plains below, where exposed by the Anakie Creek (east branch 

 of Sutherland's Creek). The Anakie creek here flows parallel to the 

 fault, a little to the east, and receives its main tributaries from the 

 high scarp bank to the west. 



There is no need to further enlarge on the proofs of faulting as 

 shown by the sections. The evidence is quite sufficient to fully 

 justify us in finally accepting this scarp as due to an extensive 

 fault. We shall retain Mr. Hart's name of the " RoAvsley Fault," 

 although it may appeal more widely to geologists as the Bacchus 

 Marsh Fault. 



The age of the fault, on geological evidence, is undoubtedly post- 

 Ordovician, post-permo-carboniferous, post-older-basaltic, and 

 post-middle tertiary, since it has intersected and thrown down all 

 these formations at various points. Both Wilkinson (ref. 56), Hart 

 (ref. 22), Gregory (ref. 21), and Andrews (ref. 1), believed the 

 feature to be pre-newer basaltic. If so it is scarcely credible that 

 the level-bedded and very easily eroded tertiary sands as shown at 

 Dog-Trap Gully, etc., could have preserved, for even a brief period 

 of time, the steep face shown in section (Fig. 7b). Moreover, the 

 sharp junction with volcanic rock at the base of the scarp at 

 Anakie Gorge (Fig. 7c), and the section asi shown at CNeill's (Fig. 

 7d), at the southern end of the fault, when considered in conjunc- 

 tion with the sections as Dog-Trap Gully (Fig. 7b), provide fairly 

 conclusive proof of its origin having been post newer basaltic. 



The basalt-filled valleys above the scarp, now exposed in river 

 sections, are comparatively shallow, suggesting that the area had 

 not been uplifted prior to the basalt Aoavs. 



There is, however, another possibility of which mention should 

 be made. In the absence of decisive proof (in the immediate 

 neighbourhood of Bacchus Marsh) of the pre-newer basaltic origim 



