100 B. K. EMERSON — TETRAHBDRAL EARTH: INTERCONTINENTAL SEAS 



overfaulted sheets CDeckschollen) in the inner chains of the Himalaya 

 and to the great overthrusts of its southern border. 



The structure of the Eur-Asiatic folds, in so far as its Asiatic portion 

 is concerned, depends therefore on a plan which was marked out in pre- 

 Cambrian time, whose development, however, extends in many parts up 

 into the later Tertiary and is probably not yet concluded. Its most 

 essential source of confusion comes from the intercalation of the ancient 

 Sinian table and in a meridional disturbance near Sailughuem. 



3. The branches of the Tian-shan abut at first on the transversely 

 striking Kirgis folds. North of Karkaralinsk the two opposing direc- 

 tions join, and not until a point is reached south of the southernmost 

 prolongation of the Ural folds do these branches obtain free development 

 and extend westward in continuity with the folded chains of central 

 Europe. The change to northward of the folding force characteristic of 

 middle and western Europe occurs at the same time. This phenomenon 

 is also of great age, as the pre-Devonian Caledonian folds prove. The 

 arrangement of the middle European folds, however, from the gneisses 

 of the Hebrides on to the border of the Alps, shows an indubitable 

 shrinking of the folding into a narrower space surrounded by horsts, 

 though made less striking by posthumous (that is, later) motions. 



The succession of the Hebridian, Caledonian, Armorican-Variscan and 

 Alpine folds is in general uniform, and is at the same time, to a certain 

 degree, the opposite of the order in Asia, where not only at many places 

 in the interior, but also almost all around the periphery new folds ap- 

 pear, as if there were still a tendency toward their extension. For this 

 reason Europe appears in still higher degree as an appendage or lateral 

 extension of eastern Eurasia. 



In relation to the Norwegian mountain region, the opinions of local 

 investigators are still so divergent that reserve is necessary for this 

 region. 



It must be further remarked that along the lines of junction that ex- 

 tend from the Thian-shan, and especially from the Hindoo Koosh to the 

 European mountains, recent movements reaching high up into the 

 Tertiary are common, and the question is not yet answered whether also 

 at the time of the Caledonian folds a connection with Asia existed in the 

 same region south of the Urals. 



It is plain, at all events, that the lithologic character of the Caledo- 

 nian outcrops of gneiss is related to that of the Hebridian foreland. 

 Further, that the older masses that emerge from the folds of the Ardennes 

 possess the characteristics of the Caledonian discordance, and that in 

 the same way in the zone of Mont Blanc and in the Carinthian Alps the 

 Variscan type is visible beneath the Alpine folds. 



