86 THE JIAIIQUETTE lEON-BEATtlNG DISTPJCT. 



of the argillites arc a.uaiii (liorite-scliists, and south of these is found a repe- 

 tition of the argilhtes. Still farther south the rocks have an in^■el■ted dip, 

 and the novaculites and argillites are found just beneath the "(piartzite 

 grouj)." From the facts oljserved with respect to the distribution of the 

 schists in the schist V)elt, the author concludes that "we must necessarily 

 infer the existence of repeated plications of the strata exposed * * * 

 and an overturned ])osition of the northern part of the layers, as the 

 uovaculites and argillitcs uuderlving them are beyond doubt the (-(juiva- 

 lents of those seen on the south side next below the (piartziti', and upon 

 the dioritic lavers, and repx'esent the uppermost beds of the dioritic rock- 

 group" (p. 32). 



Yerv nianv detailed descriptions of individual exposures are given by 

 the author, but they are not necessary to an understanding of his discussion 

 of the district. It is interesting, however, to mention the discovery of great 

 beds of conglomeratic schists in the upper })art of the "dioritic group" in 

 the neighborhoo<l oi' Deer Lake. These are spoken of as conglomeratic 

 or brecciated seams, because a jiart of the pebbles are angular nnd a part 

 rounded. "The majoritv of them consists of granular, somewhat porous 

 feldspathic substance, which on fresh fractures contrasts little from the 

 surrounding schistose mass, Init shows itself very plain on weathered 

 surfaces, on which the ])ebbles turn white or pale reddish" (p. 3fi). Other 

 conglomei'ates exist in which the schists are the groundmass and the 

 pebbles granite. Some of tliese are in the same horizon as are the Deer 

 Lake conglomerates, while others, interstratified with the schists, are much 

 lower in the series. 



The greenstones with the iron forhiation, like those near Lshpeming 

 and Negaunee, Avere regarded bv Brooks as interstratified, metamorphosed 

 sedimentar\- l)eds. Rominger, on the ccmtrary, regards them as the lower, 

 fused portions of the dioriric series that were forced up into their ])resent 

 position. In other words, he looks upon them as eruptives which were 

 forced between the beds of the iron formation as sheets, but which in origin 

 are fused sedimentary rocks, as indicated above. 



The quartzite formation succeeds the "iron group" in age, but precedes 

 it in the author's discussion of the two series in question. A number of 



