80 LIMESTONE AREAS IN QUEENSLAND 



a conspicuous conical landmark. The limestone is of 

 Devonian age, as proved by corals determined by Mr. 

 Rands. Mr. Rands gives in his report a very good 

 description of the Olsen Caves, and also of a second group, 

 the Johansen Caves, is another mass of limestone. 



The Olsen Caves, which perforate in several passages 

 the narrow limestone ridge, are in size and height very much 

 like the Chillagoe caves. The rivers or creeks which once 

 eroded them left them long ago, but the secondary lime 

 deposits, and especially stalactites and stalagmites, are 

 much less conspicuous than in the Chillagoe caves. The 

 lack of this picturesque and ornamental element makes 

 them less interesting for an ordinary tourist, but for a 

 student of physiography, the work of the running and 

 whirling waters is well preserved and very interesting. 

 The small amount of secondary limestone, and also the 

 better preservation of the caves, although the ridge is only 

 of the same elevation as over the Chillagoe Caves, shows 

 that they are in a younger stage of development. 

 Innumerable bats have their refuge in these caves, and the 

 deposit on the floor is a magnificent guano preserved by 

 nature for the use of future agriculturists. The top of 

 the ridge shows a most beautiful and diversified develop- 

 ment of the " Karren phenomena," and is more accessible 

 than the tops of the Chillagoe bluffs, the disintegration 

 being not so far advanced, and the roofs of the caves 

 solid. 



Many other limestone areas are met among the 

 paloeozoic rocks in the mountainous eastern parts of the 

 State, and their morphological development will be of 

 great help to a student of the geological changes in the 

 latest periods, since limestone more than other rocks 

 preserves the old landscape and reveals many details, 

 which serve as unmistakable proofs of older stages of the 

 drainage system. 



In the farthest north-west of tne State a high level 

 plateau called Barkly Tableland extends and continues 

 very far into the Northern Territory. The age of the 

 limestones is yet unknown, but the depth of the continuous 

 limestone strata is so enormous that it is quite possible 

 that they consist of layers deposited in very difierent 

 geological periods. Their extent is better known in the 



