BY H. C. RICHARDS. 107 



investigation of the latter is essential before anything 

 definite can be arrived at with regard to the history since 

 late ^lesozoic times. 



As has been pointed out by E. 0. Marks,^ the problem 

 of the geological ages of volcanic activity affects extensive 

 areas of coal measures, for by far the greater portion of 

 this area is made up of the Mesozoic coal-bearing sediments. 



A great portion of the area dealt with is still covered 

 with its dense virgin scrub, and this, coupled with the size 

 of the area and the extreme ruggedness of a great deal of 

 it, has rendered it impossible to prepare anything other 

 than a geological sketch-map. roughly showing the distribu- 

 tion and extent of the various rocks. 



The accompanying sketch-map, however, in a general 

 way, indicates the areas which are at present occupied by 

 Tolcanic rocks and, taken in conjunction with the various 

 sketch-sections, affords a reasonable idea of the extent, 

 distribution, and stratigraphic relationships of the rocks 

 of the area. 



The main questions which the author lias set out to 

 determine are : — 



A — The relationships of the volcanic rocks — • 



(a) to one another; 



(6) to the sedimentary and metamorphic rocks. 

 B — The geological period at which these rocks have 

 been extruded. 



II. PREVIOUS LITERATURE. 



E. 0. I\Iarks, in his paper* '"Notes on the Geological 

 Age of Volcanic Activity in south-east Queensland," has 

 summarised the various views put forward, up to that 

 time, as to the age of the volcanic activity, and he also gave 

 a list of publications i)articularly bearing on the volcanic 

 .area. 



Since then, however, there have been one or two 

 further contributions: and as it is proposed to discuss in 



'Proc. Eoy. Soc, Q'land, vol. xxiii., pt. 2 (1912), p. 139. 

 'Proc. Roy. Soc, Q'land, vol. xxiii., pt. 2 (1912). 



