FAREWELL LECTURE 271 



Indian peninsula — are included within this folding. You have heard 

 that Kinchinjinga and its neighbors, the highest peaks of the earth, 

 though within the folds of the Himalayas, still have, so far as known 

 from their foothills, the stratigraphic sequence of Gondwana Land. 



We will now take a glance at the distribution of the lines of folding 

 on the earth's surface. In the region of Lake Baikal lies an extensive, 

 somewhat crescentically arranged mass of very ancient Archean 

 rocks. It is folded, with a nearly northeast strike in the east and a 

 northwest strike in the west, and the folds are of pre-Cambrian age. 

 This old strike locus or vertex embraces Sabaikalia, northern Mon- 

 golia, and the East Sajan. Farther northwest there is developed 

 another, younger vertex, or a second center of folding — the Altai. 

 From this second younger locus proceeds an extraordinarily great 

 system of bow-shaped folds, which, in an almost incomprehensible 

 manner, embraces the entire Northern Hemisphere. The Altai 

 encircle the old vertex, and its bows repeat themselves in the east 

 from Japan and Kamschatka to the Bonin Islands. Toward the 

 west they form the broad ranges of the Tian-shan and Bei-shan. 

 Their southeastern branches appear in the bows of Burmah. In 

 front of them to the south lie the marginal bows of the Himalayas— 

 the Iranic; and farther along, the Tauric-Dinaric bows. They press 

 over the Caucasus to Europe, and form here the two previously men- 

 tioned chains of folds. 



These two chains of folds are themselves preserved in different 

 ways. The one, older, embracing the Varischian and Armoricanian 

 folds, is first discernible in Mahren. It reaches the Atlantic Ocean 

 in southwestern Ireland and Brittany, and disappears as a Rias 

 coast. Years ago, however. Marcel Bertrand called attention to the 

 fact that such a broad and mighty mountain system — on the Atlantic 

 coast it is as broad as the bows of the Himalayas — could not possibly 

 suddenly end here, but that in all probability it is continued to the 

 other side of the ocean in the Rias coast of Newfoundland. As you 

 have heard. Marcel Bertrand accordingly continued the Armoricanian 

 primary lines directly across the ocean to the Appalachians. 



Of the Appalachians, however, it has been learned in recent 

 years that they are far longer than was formerly believed. They 

 form a bow which is not, as in the Asiatic and European chains. 



