ASYMMETRY OF THE NORTHERN HEMISPHERE 99 



2. The Baikal and the region of the Angara are surrounded by a great 

 horseshoe-shaped zone of ancient faulted rocks. It reaches northeast to 

 the junction of the great Paton and the Lena (60 degrees northeast), and 

 here the folds strike southwest. On the other side they can be followed 

 northwest to a point below the entrance* of the stony Tunguska in the 

 Jenissei. Here the strike is southeast, and the same strike has been fol- 

 lowed along the Jenissei in single occurrences even as far as 68 degrees 

 north latitude. 



This great amphitheater is also open toward the north. It surrounds 

 the north Siberian plain. The Lena flows along its border in flat lying- 

 Paleozoic strata which in places extend down to the Cambrian. The 

 amphitheater is for the most part, at least, older than Cambrian. 



A fault which runs along the right bank of the Jenissei from the region 

 north of Krasnojarsk to near the mouth of the Stony Tunguska bounds 

 these rocks on the west. A second fault, probably pre-Cambrian, lies in 

 the interior of the amphitheater not far west of the west shore of lake 

 Baikal. Eastwardly the old rocks extend to the Jablonnoi, which is a 

 fault or flexure an4 not a folded chain. 



These three lines of sinking, on the Jenissei, west of Baikal, and on 

 the Jablonnoi, give this region of ancient rocks more or less the charac- 

 ter of a horst. On the south, however, on.e can not separate it from 

 folded chains in which fossiliferous Paleozoic sediments find place. It 

 is especially clear that east Sajan must be wholly separated from west 

 Sajan, and that the latter continues west, retaining its original direction, 

 crosses the Jenissei above Krasnojarsk, and finally ends west of the 

 same. 



Ergik-targak is the name of the east Sajan, and we will use this name 

 for the whole folded chain extending beyond Krasnojarsk. It appears 

 not to be sharply separated from the amphitheater of ancient rocks in 

 an orographic sense, although near Krasnojarsk lower Devonian beds 

 are involved in its folds. 



The old rocks between the fault on the Jenissei and Jablonnoi by 

 Tschita form the center of all that great series of curved chains which, 

 with manifold deviations and confusions, but yet on the whole under 

 homologous arrangement, reach from Saghalin to Java and on to the 

 Himalaya and the Persian gulf. While the} 7- form the middle, it is not 

 yet asserted that they form the point of origin of these chains. As far 

 as we can gather from single data, there appears to be, toward the mid- 

 dle of this great central mass, rather a tendency toward a sort of back- 

 ward folding of the rocks toward this center, which farther outward is 

 gradually replaced by an outward folding, which finally leads to the 



