BY H. C. RICHARDS. 123 



■stone from practical experience of its weathering qualities 

 ■cannot be regarded as a good stone. 



Lockyer Creek Sandstone. 

 This sandstone was used in parts of the Dry Dock 

 '(1877-81) at South Brisbane. It was used for coping on 

 both sides of the dock and along the quay walls, also for 

 the upper stones of the altars and for steps. The quarry 

 was midway between Murphy's Creek and Helidon and 

 apparentlj" yielded a very fair stone. The tests carried out 

 in 1875 in connection with the dock gave the following 

 results : absorption, 3.7 per cent., and specific gravity 

 2.45, giving a weight of 1531bs. per cub. foot. 



Helidon Sandstone. 

 This stone has been very extensively used and several 

 quarries have been opened in the neighbourhood of Helidon. 

 The sandstone probably forms j^art of the Walloon series 

 •of coal measures of Jurassic age. The se\ eral quarries are 

 a few miles to the north of the railway line on the sand- 

 stone ridges. The stone is variable in colour, ranging 

 through Avhite, brown and pink. For manj' years now this 

 sandstone has been largely used by the Public Works 

 Department. 



Wright's Quarries. — These quarries are situated four or 

 five miles from Helidon on the northern side of the railway 

 line on the barren sandstone ridges. The sandstone is 

 approximately^ horizontally bedded and there is very little 

 ■overburden. The quarries are all shallow excavations as 

 the stone does not extend to any depth. The beds are not 

 thick and stones more than 3-4 feet through are not obtain- 

 able although they can be got with considerable length and 

 width. Considering the nature of the quarries and the almost 

 surface character of the stones it is a matter of surprise 

 that this stone is as good as it is. The uSual improvement 

 ■of stone with depth does not hold here at all. In the 

 hand specimen the stone is seen to be made up of quartz 

 grains cemented with an abundant cement which is stained 

 brown by iron oxide. Under the microscope the stone is 

 seen to be made up of quartz grains and felspathic cement. 

 The proportion of cement is very high, being at least 50 per 

 ■cent, and present to such an extent that it is difficult to find 



