A. \VI\< 111:1.1. — RESULTS OF A.RCHEAN STUDIES. 



from a state of molten fluidity : and this vim is extended even to the so-called 

 crystalline schists and t<> many other less crystalline rocks. On the other 



hand, geologists of equal reputati ■egard the crystalline Bchists and gneisses 



as ancient marine sediments, altered profoundly by the agents which have 

 acted upon them during the vicissitudes of terrestrial history ; and this view 

 is extended also to the granitic or massive conditions of the fundamental 

 rocks. Tlie representatives of the latter school, however, admit that extreme 

 metamorphic action has sometimes reduced the ancient sediments to a Btate 

 of igneo-aqueous plasticity, and that in such condition the materials have 

 been squeezed into fissures and spaces of diversified forms. They recognize 

 the fact that large volumes of marine sediments have probably consisted of 

 volcanic ashes, lapilli, pebbles, and larger fragment- which have been spread 

 over the ocean's floor by the same agencies and in the same manner as del 1 ital 

 materials derived from eroded land-surfaces; and they, equally with the 

 opposing school, discern the evidences that lava-like eruptions have occurred 

 in every age of geologic history. 



What i- less to be expected than differences of opinion on speculative 

 questions like these is the great diversity of views respecting matters open 

 to observation. On the one hand, geologists of wide reputation and learning 

 contend that the entire series of pre-fossiliferous rocks constitutes but one 

 group or system. On the other hand, geologists equally competent recognize 

 an obvious division into two groups or systems, while some go to the extent 

 of characterizing not less than five systems beneath the oldest zone of life. 

 Those who recognize two or more pre-fossiliferous systems are nol agreed in 

 reference to their order of superposition. One maintains that the Montalban 

 i- below the Suronian, another that it is above. One affirms the Hastings 

 series to lie in the horizon of the Upper Laurentian, another places it in the 

 horizon of the Huronian. One recognizes Lower Laurentian in conformable 

 contact with the crystalline Bchists, another regards the rocks a< Upper 

 Laurentian. Systems in juxtaposition have to-day been pronounced con- 

 formable, to-morrow unconformable, and the next day again conformable. 



items have been named as holding definite chronological sequence which 



by others are affirmed to be but lithological states, having ihronological 



significance. 



With such a diversity of views entertained, not only within the deductive 

 1 >ii t also in the inductive province of the science, one can almost justify the 

 severe verdict of Whitney and Wadsworth, rendered after a searching 

 examination of the records of opinion found in American geological litera- 

 ture and thus -tated in their " Resume*: " 



\V.- think tliat it i- impossible for any unprejudiced worker in tlii- depart nl of 



nee !•> peruse with care the preceding pages and not feel obliged t" admit that the 



logy of tion of tlii- country, and especially that of Canada and New 



England, i- in an almost hopel tate of confusion. \\'<- think that it must have 



