LATERITIC ROCKS. 85 



a lateritic matrix, which conglomerate has already been referred to 

 and described when treating of the Upper Gondwana rocks (see page 80). 

 As there stated, nothing but speculation can be advanced as to the real 

 position of the small patch of conglomerate which differs so greatly 

 from all the other formations within the area of this memoir, no 

 clear evidence, whether palseontological or stratigraphical, being avail- 

 able. The petrological evidence amounts to a mere probability, but a 

 very reasonable one, that this patch of conglomerate may be an outlier 

 of the once far more widely extended Rajahmundry conglomerates. 

 These conglomerates are regarded by Mr. King as northern equivalents 

 of the group established in the south by Mr. H. F. Blanford, as the 

 Cuddalore Sandstone. 1 



CHAPTER VI.— THE LATERITIC ROCKS.] 



The formations that have to be grouped under the above heading 

 cover a not inconsiderable space in the Guntur-Ongole region, but they 

 are mostly thin superficial deposits, and really of small importance, 

 but that in parts they give character to the general surface of the 

 country. As already mentioned, they form part of the band of sedi- 

 mentary rock which generally lies between the old gneissic rocks and 

 the recent coast alluvium. In addition to the areas shown in the map, 

 this group must include sundry patches and remnants of patches of 

 shingle, mixed or unmixed with lateritic particles, which are . scattered 

 in various parts over the surface of the older rocks, especially the 

 gneiss. From their exceedingly irregular (ragged) shape and want of 

 definition of boundaries, these shingle patches could in hardly any cases 

 be satisfactorily mapped, but their presence has been indicated on the 

 Atlas maps, either by writing the words " shingle " or " gravel," or by 

 a special mode of marking ; on the reduced skeleton map attached to 

 this paper, most of these small patches had to be omitted. 



i Memoirs Geol. Surv. India, Vol.* IV, p. 165. 



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