PhysiograpJty of Werrihee Area. 243 



(4) The dissection already begun was then continued, except 

 where interfered with by the newer basalt flows. In the latter 

 cases new stream valleys were carved out, as detailed in a later 

 section. 



An important and interesting corroboration of portion of these 

 -conclusions, reached independently by Mr. Chapman (ref. 8, pp. 

 401-407), has, been recently published by that gentleman. His evi- 

 dence is purely stratigraphical, based on a knowledge of richly 

 fossiliferous beds, and connected with the first-proved extensive 

 fault in this State — that known as Selwyn's fault. A differential 

 movement of 1700 feet is referred to, and a positive elevation of the 

 up-throw side is believed to have taken place about the time re- 

 ferred to in this paper as the Older Volcanic period. This is 

 approximately the age given for the Greendale, Spring Creek and 

 other leading faults in the Werribee area. 



While the two great uplifts in the Werribee area. — the Greendale 

 uplift, and the Bacchus Marsh uplift. — arei referred to certain ages, 

 it is not assumed that the fractures themselves really originated 

 then. Rather is it possible that extensive movement had taken 

 place along them prioT to that long '* still-stand " that produced 

 •our peneplain. It is generally accepted that great faults are 

 probably not developed by a single movement, but by repeated dis- 

 placements, separated maybe by long intervals of time (Salisbury 

 *' Physiography."). Professor David (ref. 12) shows, in a general- 

 ized section, the Victorian permo-carboniferous preserved by 

 assumed faults, and such movements must be accepted to some 

 'extent to account for the preservation of such soft and friable rocks 

 during planation. To come to a much later date, there are at the 

 Ballarat School of Mines interesting and reliable records of an 

 abrupt lift of 23 feet met with in an auriferous sub-basaltic deep 

 lead, near Smeaton, compiled by the Manager of the Mine con- 

 'Cerned, Mr. J. McKenna, 1882; similar records exist from neigh- 

 bouring mines. Again, there seems no doubt that movement is 

 -still proceeding at an extremely gentle rate. Interesting positive 

 evidence of this has been noted by the writer in the New Normanby 

 mine, at Ballarat, north west of the Werribee River area. In 

 tlie western cross— cut at the 1500 foot level of that mine, there were 

 some half-dozen small faults noticeable, within a few yards, total- 

 ling a downward throw of over 8 inches. This movement occurred 

 in less than two years. At the time it was noticed, this was the 

 •deepest level on the field, so that the movement must liave been of a 

 general nature. The faults here ran along a north-south line. 



