PERMIAN PERIOD. o69 



era, limestone-making over these western regions, was prolonged into 

 another, when the limestones formed still, but with numerous inter- 

 ruptions by clay-depositions. The beds are continuous with the Car- 

 boniferous, without interruption or unconformability, and yet are 

 referred to the Permian, because they probably belong to the Permian 

 period in geological time, or, at least, its earlier portion. 



2. Foreign Permian. 

 I. Rocks: kinds and distribution. 



The Permian strata of England outcrop along the borders of the 

 several coal regions, excepting that of South Wales. They occupy a 

 small area in Ireland, about the Lough of Belfast. They consist of red 

 sandstone and marlytes, along with magnesian limestone. In Europe, 

 the Permian beds in like manner border directly upon the Coal- 

 measures ; and the rocks are similar in general character to those of 

 England. 



The Permian beds, before their relations were correctly made out, were included, 

 along with part of the Triassic, under the name "New Red Sandstone." 



They occur, over small areas, in central Germany, from southern Saxony along the 

 Erz Mountains, over the adjoining small German States, west to Hesse Cassel, and 

 north to the Hartz Mountains and Hanover. Within this area, Mansfeld is one noted 

 locality, situated in Prussian Saxony, not far from Eisleben ; another is on the south- 

 west borders of the Thuringian forest (Thiiringerwald), in Saxe-Gotha, a line which 

 is continued on to the northwest, by Eisenach, toward Munden in southern Germany. 



In Thuringia and Saxony, the subdivisions of the rocks, beginning below, are (1) the 

 Rothliegende or Red beds (called also Todtliegende), consisting of red sandstone, and 

 barren of copper ores; near the town of Eisenach, about 4,000 feet thick. (2.) The 

 Zechstein formation, or magnesian limestone, consisting of (a) the Lower Zechstein, a 

 gray, earthy limestone, overlying the Kupferschiefer, or copper-bearing shales, and the 

 still lower Wtissliegende or Grauliegende, or white or gray beds; (b) the Middle Zech- 

 stein, magnesian limestone, called the Rauch-wacke and Rauhhalk; (c) the Upper 

 Zechstein, or the Piatt endolomit, and including the impure fetid limestone called Stink- 

 stein. The formation to the southward loses its limestone. The whole Permian has 

 been called, in Germany, the Dyas, from the Greek for two, in allusion to the two 

 principal strata of which it there consists. (For an account of it, see Murchison's 

 "Siluria," and also, especially for its fossils, Geinitz's "Dyas," in 4to, Leipzig, 

 1861, 1862.) 



In Durham, England, there is (1) a Lower Red Sandstone, 200 feet thick (corre- 

 sponding to the Rothliegende of Germany); then (2), a, 60 feet of marl-slate (corre- 

 sponding to the Kupferschiefer) ; b, two strata of magnesian limestone, the lower 500, 

 and the upper 100 feet thick, separated by 200 feet of gypseous marlyte, and overlaid 

 by 100 feet of the same. The magnesian and other limestones disappear to the south, 

 near Nottingham. In Northwestern England, the Lower Permian includes 3,000 feet of 

 marlytes and sandstones ; the Middle, only 10 to 30 feet of magnesian limestone ; the 

 Upper, 600 feet, similar to the Lower. The red sandstones of Rhone Hill, near Dun- 

 . gannon, Tyrone, Ireland, are supposed to be Permian. There are detached Permian 

 areas in Dumfriesshire, Ayrshire, etc., in Scotland. In Ayrshire, they cover the Coal- 

 measures, and have some beds of igneous rock at base. 



In Russia, the two German divisions are recognized, (1) magnesian limestones inter- 

 laminated with sandstones of true marine origin, (2) overlying marlytes of various 

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