On the Geological Distribution of Gold. 31 



riches are concealed. What should be termed vegetable soil 

 is often very scanty, but where trap and basalt prevail, it 

 is produced by the decomposition of these rocks. 



The bed on which the treasures of Australia have been de- 

 posited consists for the most part of slate — siliceous, 

 chloritic, micaceous and argillaceous, — occasionally inter- 

 mixed with a very compact sandstone ; alumina and mica 

 schists being the prevailing material, and frequently found in 

 a decomposed state, termed by the miners " pipe-clay." On 

 the lower tracts, towards the sea- coast, a ferruginous and a 

 calcareous sandstone are found above the clay-becls. In 

 these localities the fluvial depositions have been proved to con- 

 tain little or no gold. 



By what is observed in various auriferous districts of the 

 world, it appears that the materials first deposited carried 

 with them the principal portion of the gold, as the superior 

 strata contain little or nothing of this metal. Clay is seen to 

 prevail in some districts, more abundantly mixed with the 

 auriferous strata than in others, and when we look into the 

 nature of the locality where the plastic clay abounds (certainly 

 very much increasing the toil and labour of the gold-seeker) 

 we find that were it not for the clay, those more abrupt and 

 narrow channels, where such treasures are found, would 

 not have retained the often diminutive gold-particles. 

 With only sand and gravel these would have been hurried 

 on too far, perhaps into the sea, and thereby lost. There can 

 remain no doubt, as to the powerful agency in the floods by 

 which these masses were moved and transported within 

 narrow spaces (the so-called gutters in the deep sinkings of 

 Australia) . Consequently, when duly considered, it will be 

 found that without the admixture of clay, many localities 

 would not have retained the treasures now accumulated for 

 the use of man. Thus, we observe from an apparently 

 insignificant circumstance, that foresight and wisdom ruled 

 in every department of geology. 



Appearance and alloy of gold distributed with the diluvial 

 detritus. — Gold, from the first fluvial depositions, is found of 

 a most varied exterior and size, from the finest dust, the par- 

 ticles of which are generally of a flat form, increasing to the 

 weight of grains, dwts., ozs., and lbs., the shapes of which show 

 the utmost imaginable variety, the surfaces being smooth and 

 often bright and clean with rounded outlines, apparently 

 what is termed " water- worn," and there can be no doubt 

 that in some localities the fluvial gold has been carried a 

 great distance previous to subsiding. 



