GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 389 



"N.W. of Mount View School, where the whole sequence 

 from the rhyolite to Lower Marine conglomerates can be 

 traced, the Carboniferous sediments dipping at about 12° 

 off the rhyolite and attaining a thickness of 400 feet. On 

 the western side the formation appears as tuffaceous sand- 

 stones, in close association with rhyolite agglomerate, and 

 containing obscure plant remains. On the eastern side the 

 greater part of the sediments has been faulted out of sight, 



save in a few places where small 

 outcrops of chocolate shales are 

 seen. 



to 



The exposure of the grano- 

 diorite in this area is probably 

 the effect of the older Mount 

 Bright fault. A glance at the 

 maps and at Section 1 will serve 

 to explain how the faulting has 

 brought down the rhyolite to a 

 much lower level and thrown it 

 against the grano-diorite, at the 

 same time exposing the latter. 



Matthews' Gap Area. — While 

 this area is continuous with the 

 others in respect of the more 

 acid lavas, the occurrence of 

 more basic rocks is better 

 marked as regards both extent 

 and variety. The rhyolite tuffs 

 appear as isolated outcrops 

 mostly confined to the northern 

 end, but nearer Matthews' Gap 

 itself the rhyolites are com- 

 pletely hidden under trachytes^ 

 basalt, agglomerate, trachy- 



