266 T. S. Hart: 



place our granitic rocks do not, as a rule, present the cliai'acter 

 of axos of even small mountain masses. The dip and ^trike of 

 adjacent rocks are little affected by them (except perhaps as will 

 be noticed below). He states ^ that the Warrenheip granite 

 affects the direction of the beds at Ballarat, but he- has stated 

 the direction of the grainite boundary \*rongly, and missed the 

 abundant evidence of folding. His argument on this point at 

 Ballarat completely fails on examination. It is far more pro- 

 bable that most of our frranitic intrusions Avere introduced by a 

 " stoping " process with foundering and absorption of the ad- 

 jacent rock overhead. In addition a Primitive Divide as early 

 as the granitic intrusions does not i>rovide for the southern 

 origin of the glacial series.^ 



With regard to Mr. T. S. Hall's suggestion, we require a good 

 deal more evidence on the matter of pitch, particularly as to 

 the extent to which it is persistent, and how it varies from place 

 to place. It majy be supposed to originate in many ways, and 

 may be consistent or inconsistent in neighbouring folds. It is 

 liable to be inconsistent if it is due to the making and dying 

 away of individual folds, or if due to local disturbance as by a 

 fault affecting a smaiU area. Besides these it is possible that 

 pitch may originate by varying intensity of the folding from 

 place to place, so that the fold is sharper at one jilace than at 

 another, and is curved in its strike. Or it may be due to the 

 fact that compression in a solid produces a tendency to expand 

 in a direction a/t right angles to the pressure, and this, if pre- 

 vented, may give rise to a simultaneous transverse folding. Or 

 it may be due to subsequent crossfolding. Or to the settlement 

 of an imperfectly supported area over an invading gi'anite. Or 

 finally to the tilting of folded blocks the folds themselves being 

 inert. 



Settlement on an invading granite might be suggested iij the 

 case of the southward pitch from Bendigo, and the northward 

 pitch from Keilor, But there are other cases which cannot 

 be so explained. Mr. W. Bara.gwanath, jun., has called my at- 

 tention to the pitch at Ballarat East, northerly at Black Hill, and 

 southerly at Magpie Gully, and neither of them near granite. 



1 Memoirs Geol. Survey, Vic, No. 4, 190". 



2 Ottifer and Ho!?<f, lot"- cit. 



