186 



VOLCANIC ROCKS OF SPRINGSURE. 



numerous fossils, including a large Aviculopecten, Prod^clus 

 subquadratus, Stenopora ovata, Protoreicpora and encrinite 

 stems. This outcrop is r.bout seven to eight miles north 

 from Springsure to^^'nship and a few miles less from the 

 alkaline trachytic rocks. The occurrence of this limestone 

 in the sedimentary series of I'ocks intersected by the volcanic 

 rocks is noteworthy in connection with the origin of alkaline 

 rocks as postulated by Daly autl others. 



Dr. Jack recorded another p?jtch of limestone with 

 similar remains three miles west of the patch above 

 mentioned, and he spe?,ks of tho limestone c/s belonging to 

 the trymi:)ie division of the Permo-Carl)oniferous rocks. Mr. 



Phoio H. C. R. 



Text-Fig. 29. — View of the eastern edge of the Mountain from the 

 Virgin Rock. The precipitous nature of the cliff face is well seen. 



B. Dunstan, the Chief Government Geologist, regards these 

 rocks as beioniiino; to the LoA\er Bowen Series. 



Petrography of the Volcanic Rocks. 



The volcanic rocks which have a total thickness of 

 about 1 000 feet are naturally developed into three divi.-ions. 



