387 



Professor W. Howchin intruding the Adelaide Series at Blinman further to 

 the south, and at Mount Remarkable, near the head of Spencer's Gulf. There 

 is every reason to regard all these as of the same age. The fact that a basic 

 dyke has been noted, *^^^) not far from Blinman, intersecting the fossiliferous 

 Cambrian strata, suggests that these basic rocks are either late Cambrian or 

 post-Cambrian in age. 



4. The ancient vesicular basic rocks from Paralana have all the appearance 

 of surface lavas, and in the absence of definite information are taken to belong 

 to the same period of activity as instanced at Yudanamutana and Blinman. 

 Neck-like forms of intrusion of vesicular basic rocks have been described 

 already from Blinman. These eruptions were possibly contemporaneous with 

 lavas, agglomerate and tuff of diabasic character associated with the Victorian 

 Heathcotian formation, which has been shown by Professor E. W. Skeats to 

 lie at the base of the Ordovician formation. 



DESCRIPTION OF PLATES XXXIII. and XXXIV. 



Plate XXXIII. 

 Fig. 1. Traversing the lower beds of the "Adelaide Series" just before entering the 

 township of Yudanamutana. The jagged peaks in the distance are at the back of the town 

 along the northern boundary of the rugged Mount Painter Belt. The area of basic intrusions 

 is within the view on the near side of the peaked ranges. 



Fig. 2. In the Yudanamutana Gorge where it intersects the great quartzite formation ; 

 the latter apparently the basal member of the Adelaide Series in this vicinity. 



Plate XXXIV. 



Fig. 1. The rugged Mount Painter Belt looking north from a point on the western 

 extremity of the Mount Gee lode. 



Fig. 2. Looking east to the elevated summit of Mount Painter itself. Taken from a 

 point on the Mount Gee lode some hundreds of feet above the adjacent valley floor. The lode 

 formation occupies the foreground. 



(All photographs by D. Mawson.) 



(15) "A Geological Traverse of the Flinders Range from the Parachilna Gorge to the 

 Lake Frome Plains," by Prof. W. Howchin, Proc. Roy. Soc. S. Austr., xlvi., 1922, p. 46. 



