﻿278 Canadian Record of Science. 



generally obtained, and in these curves a convex outer 

 side, frequently with overthrust folds, and a concave 

 inner side, often conspicuous for frequency of subsidences, 

 may be distinguished. 



If that part of the earth which is called the " Old 

 World" be studied from this point of view, that is, by 

 searching out the main lines of folding and, when they 

 are fragmentary, reconstructing them in their entirety 

 from the fragments, the general results may be summed 

 up as follows : — 



The first system of folding begins at Genoa, runs 

 through the Apennines, through Sicily, Northern Atlas, 

 bends at Gibraltar directly across the Straits, continues 

 through the Cordillera^ of Southern Spain and the Sierra 

 Nevadas, and reaches to the Balearic Islands. This great 

 curve we shall call the curve of the Western Mediterranean. 



The second curve forms the other side of the Adriatic. 

 It includes Dalmatia, Albania, Greece, stretches then 

 through the Islands of Crete and Cyprus, and finds its 

 continuation in the Taurus. This is the Dinarian- 

 Taurus curve. 



The third curve runs along the course of the river 

 Tigris, includes the Zacjjros chain, stretches along the east 

 coast of the Persian Gulf and then west of the Indus 

 towards the north to within the district north-west of the 

 city of Dera Ismail Khan. This curve includes the 

 whole of the Iranian highlands, and is. therefore, called 

 the Iranian curve. 



The fourth curve is short and reaches from Dera 

 Ismail Khan to the river Jhelum. This piece forms the 

 outer boundary of the great Hindoo Koosh mountain 

 system, and this edge is in a remarkably violent way 

 disturbed and overthrust. The edge is called the Salt 

 Eange. 



The fifth curve is formed by the Himalayas. On the 

 outer edge of these high mountains also the strata lie 



