10 On the Caves Perforating Marble 



iron, limonite, H 6 Fe 2 9 , in solution; or represent thin seams 

 laid down during the deposition of the calcareous sediments, 

 and which have not been obliterated during the processes of 

 consolidation by which it is probable these beds were meta- 

 morphosed from marine limestones into crystalline marbles, 

 I am unable to decide ; although, from the evident regularity 

 and parallelism of the seams and their continuousness, 

 together with the facts noticed when examining the structure 

 of the marble in the interior of the caves, it is probable 

 that the latter is the more correct explanation of their 

 origin. The apparent thickness of this marble bed when 

 crossed by the line of section does not exceed 250 feet. To 

 the east the slates again appear, but, at contact with the 

 marbles, very much contorted along the line of strike. 

 Crossing an eastern affluent of the Limestone Creek (Painter's 

 Creek), the porphyries are first seen, and the change is marked 

 both in regard to the character of the soil and the vegeta- 

 tion. 



On examination the rock is found to have a somewhat 

 granular felspathic base, in which are scattered numerous 

 irregularly-shaped patches of felspar, the dimensions of 

 which may generally be about a quarter of an inch by an 

 eighth of an inch in width. On ascending the hill side 

 similar rocks are to be found, nearly to the first summit, but 

 in places becoming more compact.* On descending towards 

 Stony Creek similar rocks are met with, until at lower levels 

 the slates again appear, presenting the same strike and dip, 

 and without any more than the normal state of alteration 

 as seen generally on the eastern watershed near the marble 

 deposits. On a small spur abutting on Stony Creek are 

 seen the deposits of fossiliferous blue limestone from which 

 specimen JNo. 1 was taken. 



At lower levels a tributary of Stony Creek — Round 

 Mountain Creek — has laid bare another narrow band of 

 finely laminated slates, which are succeeded by the Stony 

 Creek marbles, consisting of rather amorphous or thick- 

 bedded masses of whitish, greyish, pinkish, and variegated 

 marbles, as seen in specimens Nos. 2, 3, 4, and 5. 



In one place a ridge of undenuded porphyry remains 

 overlying the marble deposits, as shown in sketch ; while on 



* Progress Report, Geological Survey of Victoria, 1876, p. 196. A. W. 

 Howitt, F.G.S. 



