32 



must be referred to a time far anterior to all historical 

 records. The quartzites show a deeply weathered and incised 

 surface quite equal to the exposed outcrops seen in situ, and 

 are covered by lichens, and splitting by the action of the 

 weather. Further, the wash now occupies a slight rise in the 

 ground, the land sloping on either side, which would imply 

 that the interval has been sufficiently long to permit of a 

 lateral denudation that has brought the> original water level 

 above the surrounding ground. 



Since the above was written I have received a letter from 

 Mr. Baulderstone, under date April 29, 1921, to the following 

 effect: — "1 am writing you these few lines to let you know 

 that my next door neighbour (Mr. Tonken) is having that 

 stony paddock, adjoining mine, grubbed of stone ready for 

 cultivation. His men are blasting all day and are smashing 

 up all the largest stone®, but enough can be seen to make a 

 very interesting exhibit to a geologist. They will probably 

 finish turning the stones up to-day, so if you could come 

 along, say to-day or to-morrow, you would be able to get a 

 full view of about half an acre of the up -turned stones." 



I am glad that Mr. Baulderstone has a due appreciation 

 of the scientific interest which attaches to these remarkable 

 stones, so that whilst he has planted the area in which they 

 occur with trees, he takes pains that none of the larger 

 examples are disturbed. 



[Note. — It has been suggested that the transport of these 

 large stones might be due to a land-slide in the gully which 

 dammed the water back and was followed by a break-away. 

 This might be taken as a plausible alternative in accounting 

 for their presence, but it has its difficulties. The rocks form- 

 ing the sides of the gully are solid and stable. To effectively 

 block the channel would require sufficient material not only 

 to cover the floor of the valley, but to make an embankment 

 on the opposite side. There is no evidence of such an occur- 

 I'ence as having taken place either as a slide on the face of 

 the cliffs, or remnants of the talus at lower levels. — W. H] 



IV. The Occurrence of Scoriaceous Boulders in the 

 Ancient Gravels of the River Torrens. 



Many years ago my attention was called to a clay pit 

 situated between Mile End and Hindmarsh on account of 

 some unusual features that had developed in working the pit. 

 The clay had been used for brickmaking for a number of 

 years and had been worked down to a floor 20 ft. below the 

 surface of the ground. At this depth the clay ceased and a 



