1834.] Geology of the South of India. 334 



which is, moreover, always strewed with an abundance of nuclei in 

 various stages of decomposition. It is owing to the difficulty with 

 which the roots of trees penetrate this rock, that they are so rare on 

 its surface, and never grow to any size ; yet this circumstance does 

 not prevent the Andropogon contortum and nardus from growing in 

 the most luxuriant manner, which sufficiently proves the fertility of 

 the soil." ^ ' ^ 



" On ascending from the Tapti, 1 observed in a nullah, a group of 

 basaltic columns, one of which was two feet in diameter, and six 

 sided. When near the summit of the flat table land Jiltan, I 

 entered on a pass, formed on one side by a perpendicular section of 

 the rock, from twenty-five to thirty feet, and on the other, by a ra- 

 pid descent of forty or fifty. The lower part of the section, as well 

 as the pathway, is composed of the wacken, or hidurated clay, of 

 the kind I have before mentioned, of about ten feet in thickness ; 

 lying on it is a stratum of earthy clay, of different degrees of indu- 

 ration and purity, twenty yards in length, and of about two feet in 

 thickness, containing great numbers of entire and broken shells. 

 This possesses all the characters of a stratum, since the horizontal 

 fissures are parallel, and are prolonged, with a few interruptions, 

 through the whole extent. The accompanying sketch will serve to 

 give a tolerably correct idea of the mode in which the stratum ap- 

 pears to overlie the lower rock, and to have been depressed by that 

 which is superincumbent. The upper rock consists of about fifteen 

 feet in thickness of the nodular basalt, or wacken. The nuclei be- 

 ing of all sizes. The vertical fissures, which are so remarkable in 

 trap rocks, are prolonged from both the upper and lower rocks into 

 the shelly stratum, although there is no intermixture of substance." 



" The stratum is composed of a highly indurated clay, fusible be- 

 fore the blowpipe into a fine black glass, and neither it nor the 

 shells it contains, effervesce in acids. The shells are, for the most 

 part, flattened, and belong either to the genus conus or voluta. It 

 is not possible to conceive that so fragile a substance as a thin land 

 shell, should have been so completely flattened without fracture, un- 

 less it had been previously softened by some mode, which at the 

 same time produced a sufficient degree of pressure to effect its flat- 

 tening," 



*' [ have attempted, in the annexed sketch, to give a representation 

 of the degree of flattening ; but I fear that it can only be well un- 

 derstood by the specimens themselves. Neither the rock nor its 

 contained shells, effervesce in acids. Westward, the ground is cov- 



