280 CHAMBERLIN— THE INTERIOR OF THE [Apr" 24, 



in progress — that these granitic masses are not only intrusive but 

 that they were thrust into formations that had previously been 

 formed at the surface of the earth. These surface formations have 

 thus come to stand as the most ancient terranes now known. These 

 earliest accessible depositions imply the preexistence of a substan- 

 tial foundation formed at a still earlier date. Neither of these 

 gives any clear intimation that lower formations are different from 

 themselves. So far then as the record runs back, it testifies to sub- 

 stantial solidity in the outer part of the globe at least. The record 

 implies, indeed, that molten matter was then present within the earth, 

 but it gives no certain measure of the ratio of the molten to the 

 solid part. There is no determinate evidence that a molten condi- 

 tion was a preponderant state, even in the interior, at any stage cov- 

 ered by the lithographic record. The interior conditions of the 

 earliest stages that antedate the lithographic record are to be reached 

 only by indirect and remote rather than direct and immediate in- 

 ference. Under the influence of inherited presumptions, it may 

 seem to many still probable that the interior of the mature earth was 

 once dominated by a molten condition at some remote stage, but 

 the phenomena of powerful inthrusting, so often shown in the in- 

 trusions of the igneous element into the early terranes, seems to 

 imply that at the Archean stages the molten element was in the 

 strong grasp of such stresses as are natural to a rigid globe and 

 was therefore then but a minor and passive factor, not a controlling 

 one. 



When it is considered that, if the earth were once wholly molten, 

 the material for all the stratified rocks of later ages must have been 

 derived from the primitive crust after it was formed and forced 

 into positions of erosion — or from matter extruded through it — the 

 absence, according to present knowledge, of any great area of rocks 

 bearing the distinctive characteristics of the congealed surface 

 greatly weakens the assumption that the postulated molten state 

 ever obtained in the mature earth. 



A study of the stress-conditions of the interior of the earth 

 seems to call for a similar reversal of the inferences once drawn 

 from the igneous rocks. From the earliest well-recorded ages, the 

 exerior of the earth has given evidence of broad topographic reliefs 



