376 E. H. L. Sc/marz — Gold in Ca^je Colony. 



lateral secretion ; the process of leaching out the gold in the banket 

 and depositing it in the reefs I term the second stage. The third 

 stage is the displacement, mechanically or chemically, of the gold in 

 the reefs and the building up or the deposition of gold nuggets in 

 the alluvial gravels. 



In this stage must also be included the surface enrichment of the 

 reefs, caused by the concentration of the precious ores from portions 

 of the reefs that have been removed by denudation. The quartz, 

 being more homogeneous than the sandstones which it traverses, 

 stands out somewhat from the surface when exposed to the 

 influences of denudation, but it soon crumbles up, and the particles 

 get washed down with the rest of the detritus ; the gold, however, 

 tends to stay where it is, owing to its great density. When the 

 water which has slowly percolated through the rocks, and has taken 

 up certain quantities of ferric sulphate, gets to the quartz-vein, it 

 slowly dissolves the gold in it, and then becomes lodged in the vein, 

 splintered by surface-weathering agencies. So, either by mechanical 

 means or by chemical means, the surface of a quartz-reef tends to 

 become far richer than it is in the bulk. Pieces of enriched surface- 

 reef have been found so studded with gold that the poor prospectors 

 thought that at last they had got the parent reef of all the alluvial, 

 but no body of reef has been found carrying gold in appreciable 

 nuggets. 



The process that I have outlined to explain the surface enrich- 

 ment of reefs is the same for the formation of gold nuggets. These 

 are found in the alluvial gravels of the creeks, but especially in mud 

 in the crevices in the sandstone and under great boulders, and 

 are found in considerable quantity. There is no law enforcing 

 registration of gold finds, and many thousands of pounds' worth of 

 nuggets have been passed into the bank without notification, but, for 

 all that, from the proclamation of the fields in 1887 to March, 1905, 

 a total of 3,370 ounces has been registered. I was led to bring in 

 the explanation that the nuggets must have in great part been built 

 up from solution, and are not merely jiarticles that have been washed 

 out of the reefs by the following considerations : — 



1. With the exception of a very few instances, no reef^ have been 

 found containing gold in nugget form. 



2. The nuggets, running up to three and four ounces, are found 

 in places where it would be difficult to explain their presence, that 

 is to say, in narrow crevices and hollows surrounded with light 

 sand. One would have to explain how these large nuggets got 

 pushed past obstacles if we are to consider them as having been 

 mechanically brought into place. 



3. Many of the nuggets, although occurring in the stream-bed, 

 show quite sharp ridges and points, so that they cannot have travelled 

 very far, yet there is no source near at hand whence they could have 

 been derived. 



4. The creeks and gullies contain gravelly patches which are 

 washed out and all the gold recovered ; a few seasons later the same 

 hollows are worked and the gravels are found to be as rich as before, 



