CxEOLOCICAL EXPLORATIONS AND LlTEKA'i IKE— ism. 121 



oil the oiie liand, and into the more distinctly deveh)ped chhjiitic and h((rnbleudic 

 schists on the other. As a rule these varions schists present no parallel structure 

 other than that which seems referable directly to secondary causes; that is to say, 

 they do nor present such banded varieties as would suggest the action of sedimenta- 

 tion during their production. Uowever, such banded varieties do occur in sulxndinate 

 quantity, pre.senting then very strikingly regular, rapid alternations of light and dark 

 bands. (P. ll.j 



111 sdiue ])l;u-es within the greenstone areas there <iccur scliists with 

 a more (.r less obscure frag-mental appearance, which is nuich more pro- 

 nounced on tlie weathered surface than on the fresh fracture. As a rule 

 these schists are without any paralhd structure except tlie shitv ck^avao-e 

 which all the g-reen schists present. Among them are the rocks observed 

 by A. Wiiichell and N. TI. Winchell at Deer Lake. 



In his description of the map (PI. Ill, fig. 2) accompanying his paper 

 the author writes (pp. 14-1.")): 



The line of demarkation between the schists and the granites * • * is not 

 a sharp one, since the two seem to mingle more or less confusedly tm each side of the 

 somewhat arbitrary line indicated upon the map. Southward of this greenstone- 

 scthist area * * * are belts of country occupied mainly by detrital rocks, such as 

 quartzites and various fragmental slates; with these, however, are large bodies of 

 crystalline limestone and several phases of ferruginous schist, all of which have in 

 common an entire lack of anything like a fragmental texture. In addition to these 

 rocks these areas include also sheets of diabasic greenstone, which are interbedded 

 with the detritals and ferruginous schists alluded to. 



The autlior contrasts the schists with the detrital rocks to the south of 

 them. He agrees with the earlier workers in the district as to the inferior 

 position of the greenstone-schists with respect to the stratifonn series, and 

 as to the intrusion of the schists by the granite. But he disagrees with 

 previous geologists who regarded the green schists as belonging in the 

 stratiform series and the granite as younger than the detrital series. 



In other words, it thus far appears to me that there is good reason to believe 

 that these greenstone-schists along with the granites, gneisses, etc., form a portion 

 of the basement upon which the overlying detrital iron-bearing series was once hori- 

 zontally and unconformably spread. 



The granites are shown to be unconformably beneath the detrital 

 series and to be at the same time younger than the greenstone-schists; 



