GRITTY SANDSTONES. 35 



hoped re-examine these localities, and perhaps have the good fortune to 

 find organic remains which will admit of settling the geological horizon 

 to which these shales belong. 



To the Rajmahal series it will, perhaps, be best to refer certain remark- 

 able boulder beds resting on the surface of the 

 Boulder beds. « « • 



gneiss on the high grounds north-east or Siva- 



ganga and north-west of Seruvayal (Seruvial). These boulder beds 

 appear to be due to the action of surf beating on shoals ; for not only- 

 do many large and well-rounded pebbles and small boulders strew the 

 surface, but the surfaces of various protuberances of the coarse 

 granular gneiss are worn and rounded in situ. These beds are very 

 thin, mere remnants in fact of more extensive formations. They bear 

 a greater likeness to the boulder beds found at the base of the Hajmahal 

 series near Utatur (Trichinopoly District), Sripermatur (Chingleput 

 District), and Ongole (Nellore District) than to any boulder conglo- 

 merate in the cretaceous system or in the Cuddalore sandstone and 

 Jateritic series. These boulder beds are best seen along the road leading 

 from Natarashenkotai north-north-westward to Kallayar Mangalam. 

 Their extent could not be exactly ascertained owing to the great devel- 

 opement of thick scrub jungle, the absence of all available land marjis^ 

 and to the badness of the map (sheet 80) which is there utterly 

 wanting in definition. They lie at a considerably higher level than 

 much of the gneissie area to the west of them. No section was met 

 with showing the position of these boulder beds relatively to the over- 

 lying lateritic beds. 



CHAPTER V. 



THE GUITTY SANDSTONES (cUDDALORE SERIES ?) . 



All along the coast of the Carnatic from the valley of the Godavery 

 southward to that of the Cauvery occur at intervals deposits of coarse 

 and generally rather friable sandstones and grits with occasional conglo- 



( 35 ) 



