256 THE CANADIAN NATURALIST. [Jan. 



periods, and especially characterised the latter. The occurrence 

 of porphyritic conglomerates in Germany is similarly limited. On 

 this point Zirkel says : " As porphyritic eruptions principally fall 

 " in the period of the Bothliegende, so the whole of the clastic 

 " rocks of the porphyry family stand in close connection with the 

 " deposition of its strata, to which they have also contributed a 

 " considerable amount of material. For instance, coarse porphy- 

 " ritic conglomerates form members of the Upper Rothliegende 

 " in the Oschatz-Frohburg basin, in the Dohlen basin, at Wieser- 

 •• st licit in the Hartz, and in the north-western part of Thiiringia. 

 " At Baden, in the Black Forest, the deepest strata of the 

 " Bothliegende consist of porphyritic breccia and the middle 

 " strata of conglomerates." * Even polygenous conglomerates, 

 such as those above-mentioned, are especially frequent among the 

 carbcniferous and permian strata of Europe. Naumann thus 

 briefly characterises the Bothliegende of Germany, which he 

 considers as equivalent to the English lower New Bed Sandstone 

 and the French gres rouge : " The Bothliegende appears in so 

 " many of the countries of Germany, and iu such great thickness, 

 " that, in its mode of development there, we recognise the normal 

 " type of this remarkable sandstone formation. The pigment of 

 " the sandstone, consisting principally of iron-oxide, the frequent 

 " occurrence of conglomerates, the often repeated change in the 

 " size of grain of its rocks, the association with porphyries and 

 " melaphyres, the very frequent layers of claystones and porphy- 

 " ritic conglomerates, the great poverty, and often complete 

 " absence of organic remains, — all these are characters by which 

 " the Bothliegende is distinguished as quite a peculiar sandstone 

 " formation."-]* That not one of the peculiarities here emphasised 

 by Naumann are absent from the upper group of the Upper 

 Copper-bearing rocks of Lake Superior, will be evident to any 

 one who has observed them or carefully gone through the 

 description above given. It therefore becomes a matter of much 

 importance, and deserving of the most careful study, to ascertain 

 whether this resemblance is a mere coincidence, or whether there 

 is reason for supposing that any part of these Upper Copper-bearing 

 rocks are of Permian age. 



* Zirkel ; Petrographie. Vol. ii., p. 529. 



t Naumann ; Lehrbuch der Geognosic. Vol. ii., p. 584. 



