824 REPORT— 1890. 
that the rainfall which fed this and other lacustrine deposits came from higher 
ground to the east, as the course of all the streams from the Holderness and Filey 
boulder clay is westwards. 
3. On the Origin of Gold. By Professor J. Locan Lostey, F.G.8. 
After pointing out that it was not the origin of auriferous veins, but of the 
gold itself that was the subject of his paper, the author, from facts recently made 
known, showed that while geological evidence is against its igneous origin, all the 
gold of all the rocks may have been derived from aqueous deposition—that, in 
fact, all this gold may have been deposited by marine action in the same way as 
the materials of the aqueous rocks themselves have been. And, moreover, that 
our unaltered sedimentary rocks, even of Tertiary age, may contain an equal 
amount of gold in proportion to their bulk with that of those altered or metamor- 
phosed Cambrian and Silurian rocks, which have hitherto been regarded as the 
earth’s great treasures of the precious metal. 
The knowledge now possessed of Secondary and Tertiary auriferous veins in 
California controverts the Plutonic as well as the Palzeozvic hypothesis, and the 
discovery of gold in sea-water and of its precipitation by organic matter alters the 
position of the question from that it occupied in the days of Murchison and 
Forbes. 
If gold was originally derived from Plutonic sources it ought to be found among 
volcanic products which come from the same deep-seated sources, and only differ 
from Plutonic rocks in being solidified under different conditions. But gold, although 
a most widely distributed metal, is almost, if not quite, unknown as a product of 
voleanic regions. This is strongly against its igneous origin, and consequently 
points to the gold of the Paleozoic auriferous veins being derived by removal from 
sedimentary rocks in which it had been originally deposited. This removal could 
be effected by chemical combination, solution, infiltration, and segregation. Since 
silica may combine with gold under heated conditions, and the silicate of gold so 
formed be soluble in hot water, asis also silica, gold in the form of silicate could be 
carried by water, heated by deep-seated conditions or by the neighbouring uprise 
of fused matter, from its original position, and be deposited in veins with silica 
itself, when subsequent segregation would separate the silica of the silicate of gold 
and leave it as free gold imbedded in quartz as it is now found. 
The discovery by Sonstadt of nearly a grain of gold to the ton of sea-water 
shows that the sea has always held in solution an ample store to give to its sedi- 
ments the amount of gold they aze now found to contain, and Daintree’s discovery 
of the power of organic matter to precipitate gold from a solution of the ter- 
chloride explains the deposition of gold from sea-water, since on the sea-bottoms 
there has always been a large amount of organic matter. 
Though the gold so deposited would be in infinitesimal proportion to the mass 
of the marine mineral sediments, it would be aggregated by nuclei of metallic sul- 
phides by which it would be retained until thermal conditions favoured its conver- 
sion to a soluble silicate. The sulphide of iron, or pyrites, is known to nearly 
always contain gold, and hence it is to be concluded that the gold of the sedimen- 
tary rocks which have not been subjected to the favouring conditions for its separa- 
tion and preservation in quartz veins is now in the metallic sulphides these rocks 
contain. In such rocks as the Chalk and the London Clay, the amount of pyrites 
is very great, and the author concluded by giving a rough estimate of what may 
be the amount of the gold now in the surface-rocks of the south-east of England, 
from which it appears that these deposits may contain gold to the value of 
100,000,000Z. sterling. 
4. As to certain Alterations in the Surface-level of the Sea of the South 
Coast of England. By R. G. M. Browne, I.G.S. 
With reference to the alterations everywhere observable, which have taken 
place in the positions, relatively with each other, of the land and sea surfaces, the 
author suggests that the mode in which such alterations have occurred’ does not 
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