PHYSIOGRAPHY OF SOME LIMESTONE AREAS 

 IN QUEENSLAND. 



By DR. J. Y. DANES 



(Prague, Czech University). 



Read before the Royal Society of Queensland, 

 July 23, 1910. 



During my stay in Queensland I had occasion to pay 

 more or less hurried visits to three important limestone 

 areas within the limits of the State, and I was able to make 

 some observations about the present state and the develo^)- 

 ment of some prominent and generally interesting features, 

 which distinguish the pure limestone from most other 

 common country rocks. 



Pure limestone differs conspicuously from many 

 other rocks by its comparatively easy solubility through 

 the action of water charged with a slight quantity of 

 carbonic acid. The water widens the joints and clefts 

 in the rock structure, and tries to force a passage vertically 

 into the depths. Where the vertical progress is impossible, 

 the water proceeds more or less horizontally, or follows 

 the inclination of the beds, and starts again in the vertical 

 direction if possible, until it reaches the base of the 

 previous rock or the upper level of the underground water. 

 The disintegrating action of the water upon the neighbour- 

 ing rock is slow in the beginning and purely chemical ; 

 but later on the cavities become so wide that the running 

 water starts on the mechanical work, grinding the rocks 

 with sand and gravel set into rotatory movement by 

 vertical whirls, or scratching the surface with the same 

 material, where the passage is more or less horizontal and 

 unobstructed. Subterraneous passages, extended systems 

 of caves, are results of that process, and their jH-esence is 

 the most characteristic feature of the limestone areas,. 



