R. D. Trving—Divisibility of the Archean. 241 
© proof advanced of a great break, inasmuch as, even at the 
present time, eruptives of modern origin are having geologically 
contemporaneous sediments piled against them. The mere 
superposition of sediment upon an eruptive is no proof of a 
geological hiatus between the two. In answer to this argu- 
ment it is to be said that the case we are considering finds no 
parallel among such modern occurrences. e gneisses, schists, 
granites, etc., forming our supposed eruptives, are, if eruptive, 
manifestly not to be compared with the lavas of modern times. 
n the contrary, their completely crystalline character and 
general structure would force us to believe that they solidified 
far within the depths of the earth, and that, therefore, before 
they formed the bottom of the sea within which the slaty beds 
were accumulated, they must have been subjected to an enor- 
mous atmospheric erosion; and t 
evidence here of the existence of a genuine geological break, 
ven on the view that the more southerly rocks are all eruptives. 
But an eruptive origin for all of these rocks, thus admitted 
scale. Now, if these gneisses and schists are of sedimentary 
origin, then they certainly passed through processes of disloca- 
