Fhysiography of Werrihee Area. 231> 



of this cliff there is evidence of the fault D, older basalt lying 

 against the glacial with an almost vertical junction; the section 

 more upstream is soil-covered, but quite clear, the lower one is 

 bare, and shows the decomposed basalt and glacial sandstones with 

 a steep line of contact. 



Continuing this line down-stream, however, an excellent section 

 IS found. Where the fault D crosses the Korkuperrimul, just 

 above the letter D in Fig. 10, a cliff section, 20-30 feet high, shows 

 the junction as depicted in Fig. 11. This last-mentioned fault in- 

 creases in throw towards the south ; at the north end a small cliff' 

 of glacial, with overlying basalt, occurs in the creek on the left 

 bank. 



(f) Other small Faults. — The preceding faults comprise all those 

 of which the evidence is held to be satisfactory. As already men- 

 tioned, it seems undoubted that certain areas, especially the Ballan 

 sunkland, structurally consist of a mosaic of faulted blocks. Mr. 

 Baragwanath, who is at present tuigaged in a geological survey of 

 the parish of Gorong, etc., ha« a good deal of evidence pointing 

 in the same direction ; much of this the writer has had the pleasure 

 of examining with him in the field. The evidence for the faults 

 is mainly provided by the older basalt and glacial beds, and many 

 of them are suspected" to be of the nature of the Bald Hill Fault. 



(iv.) Previously demonstrated Fault s .— These are dealt with as r 



(a) Selwyn's Fault and others, 



(b) Faults near Geelong. 



(a) Selwyn^s Fault. — This very extensive and dominant fault 

 (see h. Fig. 5, for plan), some fifty miles long, and with its chief 

 down-throw (over 1700 feet) to the west, was first mentioned by 

 Selwyn in 1857 (ref. 27), and has been frequently referred to since. 

 In a map oi Australia's Tectonic features (ref. 12) a north-south 

 fault is shown cutting through Port Phillip, and hading west; 

 it is labelled '' Sorrento fault," and may refer to the one now 

 being discussed. 



What is believed to be the northern continuation of this fault has 

 more recently been mapped by Morris (ref. 38), who states that the 

 down-throw of this fault (referred to by him as the Montrose fault) 

 is to the eastward, in the neighbourhood of the Dandenongs; he 

 therefore regards the whole fault as *' pivotal." The same writer 

 has also published accounts of the Olinda fault (E.-W.), in the 

 Lilydale aiea. and the Evelyn fault, hading east and parallel ta 

 the Montrose fault, about two miles further east. 



