REPORT OF THE DIRECTOR I920-2I IO5 



schists) and the Vindhyan group (sandstone, shale, limestone), 

 which probably corresponds in age to a large part of the Paleozoic 

 era, but has not yet furnished fossils. The gneiss-mass of the 

 Archean is exposed from Ceylon along the east coast to near the 

 bend described by the Ganges and at i6° latitude on the west coast. 

 To this great dominant mass of Archean rocks, two smaller ones 

 must be added; one situated in Bundelkhand, and the other dis- 

 tributed in long folds and ridges forms the Aravalli mountains 

 on the northwest border of the peninsula. Suess emphasizes the 

 facts that these Aravalli mountains which strike with their compos- 

 ing rocks in N 36° E direction " present us with one of the most 

 ancient folded ranges to be seen anywhere on the globe " (ibid., 

 p. 402) and " that, the strike of these primaeval folds is completely 

 independent of the trend of the existing great mountain ranges of 

 India " (ibid., p. 403). Far to the north, on both sides of the river 

 Chenab, in the isolated Korana mountains, we find even a mountain 

 range composed of rocks which resemble the ancient quartzites and 

 schists of the Aravalli and whose ridges strike northeast-southwest 

 and approach to within 65 kilometers of the outer border of the 

 great folded mountains of the Himalayas. 



Lake (1893, p. 309), who since Suess has discussed the " Growth 

 of the Indian Peninsula," divides the Pregondwana division into 

 the Gneissic, Dharwar " Transition " and Vindhyan series; and 

 distinguishes three main masses of gneiss, namely, the southern 

 mass, the Bundelkhand mass and the northeastern mass. The 

 southern mass is described as consisting of gneissic and granitoid 

 rocks, traversed by a number of nearly parallel bands of schist, 

 together with conglomerates, hematite beds and lava flows, to 

 which has been given the name Dharwar series. " The direction 

 of the bands is NNW-SSE ; and it is clear that the Dharwars originally 

 covered the whole, and that they were afterwards thrown into folds 

 running NNW-SSE. . . . The folding and denudation of these rocks 

 was completed before the deposition of the next set of beds, 

 which were laid down as a fringe on the N, NE and E sides of the 

 gneiss mass. . . . Those on the east side (Kadapah basin) lie quite 

 flat on the gneiss in the western part, on the eastern side they 

 are folded, the direction of the folds is N-S. The same condition 

 holds true of the Godavari basin, to the north of the southern gneiss 

 mass. On the northeast of the gneiss mass (in the Kaladgi basin) 

 the beds have been thrown into folds running W by N to E by S." 



The direction of the folds of the Bundelkhand mass is not given 

 by Lake. 



