298 Chemical Origin of Iron Ores, Etc. — Winchell. 
Hunt states :'^ "Those chemical compounds which were 
most stable at the elevated temperature then prevailing would 
be first formed. Thus, for example, while compounds of oxy- 
gen with mercury, or even with hydrogen, could not exist, 
oxides of silicon, aluminum, calcium, magnesium and iron, 
might be formed. * * * * All the elements, with the 
exception of the noble metals, nitrogen, chlorine, the related 
haloids, and the hydrogen combined Avith these, would be 
united with oxygen. The volatility of gold, silver and plati- 
num would keep them still in a gaseous condition at temper- 
atures where silicon, and with it the baser metals, were precip- 
itated in the form of oxides." 
These quotations might be multiplied. The formation of 
siliceous and irony deposits from oceanic waters is referred to 
by Gustav Bischoflf,'' J. W. Dawson '^ and by nearly all geolo- 
gists who have written of the chemical reactions of the prime- 
val ocean. Much speculative literature has been published 
relating to the early co-relations of the consolidating crust, the 
heated interior and the enveloping atmosphere of the earth. 
But very often no actual account has been taken of these theo- 
ries in the practical work of the field-geologist. The drama 
of sedimentation and the erosion of shores and the transpor- 
tation of material by currents, forming the later strata of the 
super-crust, have been duly investigated, but this theoretical 
age of seething, alkaline, oceanic water, the actual causes that 
produced it, the resultant rock that attests its existence, and 
the position it holds in the strata of the Archaean, have not 
had their analogous demonstration and adequate description 
in geological literature. The writers believe the Keewatin age 
was characterized by these forces and events, and that the 
green schists, whether sericitic, or chloritic, or diabasic, that 
fundamentally constitute the bulk of its rocks, and the jaspi- 
lyte lodes, exemplify the chemical precipitations and 
mechanical depositions that the theories require. So long as 
the term Huronian was made to cover the actual Huronian 
strata as well as all lower beds down to the Laurentian base, 
it was difficult, if not impossible, to invoke world-wide forces 
^«T. Sterrj' Hunt. Smithsonian Eeport, 1869.pp. 186, 189. 
^'' Chemical and physical geology. (Cavendish Society), vol. i. pp. 
143, 14G. 
'*" Quart. Jour.'Geol. Soc. vol. v. p. 25. 
