43 



GEOLOGY OF TEIClIINOPOLy;, &C. 



[Chap. III. 



£■§ 



doubt whatever^ as the contact of the laterite and 

 gneiss is exposed to view in many places. 



Mr. H. F. Blanford has assumed that no srrits 

 extend to the westward of Vellum -j it is true that 

 none are exposed on the high ground west of the 

 great Vellum nullah, but the whole of the ground 

 there is so thickly covered with dark red soil and 

 black laterite, that the nature of the underlying 

 rock cannot (or could not at the time of our 

 visit) be determined. But the lower beds of the 

 grits are unquestionably exposed in the nullah close 

 to the village of Vanarapata, and as the eastward 

 dip of the whole formation, is very slight, there 

 seems every reason to believe that it extends west- 

 ward across the horse-shoe-shaped valley of the 

 Vellum nullah, and thins out on the gentle slope 

 of the gneiss between Vellum and Singiputty. 

 If the grits do not die away on the gentle slope 

 of the gneiss, they must abut suddenly against a 

 head-land of it, and it seems very unlikely that 

 this could be entirely hidden by the talus of red 

 soil and laterite. 



Further, the general outline of the rising ground 

 on the west side of the nullah does not indicate 

 any change of rock to have taken place. 



The sudden termination of the grits at Vellum 

 would only make the overlap of the laterite much 

 greater than we are inclined to regard it. 



The accompanying Section, Fig. 1, will help 

 to explain the true nature of the overlap. 



The red soil and black laterite identical (in 

 Boundary of laterite 'ippearance) with the surface 

 *° ^''*- laterite (east of Vellum) ex- 



tends to about 5 miles west of Singiputty. The 

 laterite then suddenly ceases and gives place to a 



(^64) 



