IN THE NOETH-EASTEEN" CAEPATHIANS. 675 



where the streams have cut through the loess, there occur in its 

 lowest parts small rounded fragments of Carpathian Sandstone, and, 

 mixed up with these, isolated larger and smaller erratic blocks of 

 red granite and orthoclase porphyry — more rarely of gneiss and 

 diorite. The whole of the diluvial deposits rest immediately on the 

 Carpathian Sandstone. But there occurs at Przemysl yet another 

 very peculiar accumulation of blocks, which is very different from 

 the deposits described above as ' erratic' The hills on the south side 

 of the Sau valley, whose mean height is about 370 metres, are paitly 

 covered, over the lower portion of their northern slope, with a chalky 

 loam, in which numerous rounded blocks of a light compact Jura 

 Limestone lie bedded. Similar blocks occur in great numbers on the 

 plains round the village of Kruhcl-Wielki, where they have been 

 quarried in pits 2-3 metres deep." 



C. Brief Description of the Rock-formation round the Head-waters 



of the Theiss. 



It was with the view of searching after traces of glacial action, 

 and of comparing with their Scotch representatives any deposits 

 which might cross our path, that we traversed in the autumn of 

 1874 one or two of the more important valleys in the eastern part 

 of the chain. We selected the valleys of the Theiss and the Pruth 

 as being among the largest lines of drainage in the north-eastern 

 region. The former river receives many important tributaries before 

 it issues from the range and enters the great plains of Hungary. 

 We therefore inferred that, if a glacier once filled the Theiss valley, 

 it must have been swelled by many accessions along its course, and, 

 consequently, that the moraines or other glacial deposits would 

 naturally accumulate in considerable force near the edge of the 

 plateau. Our hopes were in some measure realized, though not to 

 the extent we had anticipated. 



Before stating the results obtained by us, it may be advisable to 

 sketch in a single sentence the various rock-formations which make 

 up the structure of that portion of the Carpathians surrounding the 

 head-waters of the Theiss. While passing through Vienna, we pro- 

 vided ourselves with the maps published by the Imperial Geological 

 Institute, on the scale of about 9 English miles to an inch, which 

 were of the greatest service to us along our route. From these 

 it may be seen that along the western slopes of the chain between 

 the crest and the right bank of the Yisso, one of the tributaries of 

 the Theiss, there stretches a mass of highly crystalline strata. 

 These mica-schists &c. (Glimmer-Schiefer, Primarformation), cross 

 the Theiss between Trebousa and Bocsko Raho in an attenuated 

 form, and eventually die out a few miles to the north-west. Here 

 and there occur lenticular patches of Dyas (Permian) and Creta- 

 ceous rocks ; but in this region by far the greater portion of the 

 plateau is composed of a group of strata of Eocene age. These 

 sandstones, clays, and shales, known by the name of the Flysch 

 beds, attain a wonderful development, not only round the head- 



