TACONIC QUESTION IN GEOLOGY. ISS 



large part of crystalliue schists, — the argillo-talcose schists of Favre, the gray lustrous 

 schists of Lory, the sericite-schists and the gJanzschiefer of others. This schistose series, to 

 which a great thickness is assigned, includes quartzites, dolomites, micaceous limestones, 

 banded and statuary marbles, serpentine, talc, karstenite and gypsum. These rocks, which 

 among other localities, are well displayed on the line of the Mont Ceuis tunnel, have been 

 by many Alpine geologists regarded as altered Jurassic or triassic. This view was, however, 

 in 18*72, combatted by the present writer, who then referred them to primitive or eozoic 

 time ; a view which has since been accei)ted by Favre, who had previously regarded them 

 as mesozoic.'" Their pre-paleozoic age was afterwards maintained by Gastaldi, by Fillet, and 

 by Jervis. I have since called attention to the fact that these lustrous schists greatly 

 resemble those of the Taconian of North America, to which I have compared this whole 

 Alpine series. In it are included, by Gastaldi and Jervis, the schists of the Apuau Alps 

 with their crystalline marbles, all of which, as seen in the mountains of Carrara, I have 

 found to resemble the Taconian closely. These marbles, it may be remarked, have, like 

 those of the American Taconian, been referred to very different geological horizons, having 

 been successively called altered cretaceous, liassic, rhaetic, infra-carboniferous and pre- 

 paleozoic, to which latter position they were assigned by Gastaldi in 18^4. 



§ 208. To the same horizon, apparently, belongs the Hercynian Primitive Clay-slate 

 series, which, according to Giimbel, intervenes in Bavaria between the Hercynian mica- 

 schist group and the fossiliferous Cambrian strata, by which it is overlaid. This clay- 

 slate series includes beds of crystalline limestone, sometimes magnesiau, attaining in places 

 three hundred and fifty feet in thickness, which contain hornblende and serpentine, and 

 a form of Eozoon, named by Giimbel E. Bavaricum. It also includes siderite, which, by 

 epigenesis, gives rise to valuable masses of limonite. The history of the group of lustrous 

 schists in the Alps, and their related rocks, has been recently discussed at some length 

 by the writer in a chapter on the geology of the Alps and the Apennines, contained in 

 an essay on "The Geological History of Serpentines, etc.," to which the reader is referred 

 for details and for authorities.'' 



In some parts of central Norway, the fossiliferous Cambrian, or so-called Primordial 

 zone, is described by Kjerulf as resting directly upon the ancient gneiss, but in other parts 

 it is underlaid by a series which, from the presence therein of detrital beds, is designated 

 as the Sparagmite group, and sometimes attains a thickness of over 2,100 feet, as in 

 Ostdalen. This underlying series, which itself rests upon the gneiss, includes red and 

 grey sandstones and conglomerates, with considerable masses of limestone and of dolomite, 

 besides various fissile rocks described as black argillites, lustrous schists, sometimes tal- 

 coid, and schistose quartzites. It is without observed fossils, and has been by Kjerulf 

 compared with the Lower Taconic.^" 



§ 209. The recent studies of Barrois in Spain, published in 1882, appear to throw a further 

 light on the Alpine series which we have compared with the Taconian. The paleozoic 

 rocks, containing at their base an abundant Cambrian fauna, are found in the province of 



■''"Hnnt, The Geology of tlie Alps, Amer. Jour. Science, vol. iii, pp. 1-15 ; .also Clieni. and Geol. E.S3ays, pp. 336, 

 347, 348. 



^^ Trans. Koy. Soc. Canada, vol. i, sec. iv, pp. 186-196. 



^- Hunt, Azoic Rocks, p. 131, and Kjerulf, Udsigt f)ver det Sydlige Norgea Geologi, 1S79, pp. 128-138, and the 

 accompanying Atlas, plates xxvi, xxvii. 



