HY W. 11. TWELVETRKKS. 49 



stone. I recognised it as an aboriginal Flake, Ijut, to make 

 sure, I submitted it to Mr. R. M. Johiislon, wiiose know- 

 ]edgc of these implenieiits is unrivalled, and lie at once 

 pronounced it to be of human workmanship. 



The following day I proceeded to the claim in order to 

 examine the conditions of occurrence. The actual block 

 of gravel from which the stone had been picked had dis- 

 appeared 111 sluicing, but I stood on the actual site of the 

 discovery, and Mr. Richards, who enjoys a high reputation 

 for reliability and integrity, explained to me all the 

 attendant circumstances. 



The mine owners are sluicing tin ore fi'om a bed of 

 gravel 2h to 4 feet thick, which underlies 10 to 20 feet 

 of a drift which has been deposited all over this plain 

 by the sea in former times. This overburden of drift 

 has to be removed before the wash gravel is exposed. In 

 the course of working, an excavation lias been made below 

 the surface of the ground about half a chain wide and 

 10 feet long with a maximum depth of 'JT) feet. 



After bringing down the overburden at the west end 

 of the excavation by ?iieaiis of a stream of watei', a block 

 of wash or gravel, here 2\ feet thick, was detached from 

 the cliff face at a de]:)Hi of 10 feet fioni the surface, and 

 from the top of this block Mr. Richards picked out the 

 flake in question, noticing that it was a different kind of 

 stone from any he had previously seen in the wash. It 

 was slightly adherent to the gravel, and broke in two pieces 

 as he handled it. Not attaching any particular importance 

 to it, he did not preserve the piece which was broken off. 

 On examining the plane of fracture, a deposit of silica is 

 noticeable on the surface of it. I examined the working 

 face closeiv, with a view of seeing whether it was at all 

 possible for the stone to have been derived from the 

 surface, but the possibilitv seemed to be quite excluded. 

 The two facts that it. was adherent to the wash, and that 

 silica had crystallised on the fracture plane, add additional 

 weight to the conclusion that the stone belonged to the 

 wash. 



We are shut up to the conclusion that it is the handi- 

 work of aboriginals who lived at the time of the deposition 

 of the wash (probably a beach deposit) and prior to the 

 accumulation of the overlying marine sands. It is not 

 waterw^orn. INTost of the stones in the wash are well 

 worn by the action of water, but there are some among 

 them which are absolutely angular, though they have to 

 be looked for. 



The question arises what amount of denudation have 

 the overlying drifts undergone since deposition? Is there 



F 



