Reviews— Geological Survey of South India. 313 
Dea AV Apa RSH WA Ss 
—_—_.——_ 
J.—Skxercn or tHE Work oF THE GxrotocicaL Survey In SoUTHERN 
Inpra. By R. Bruce Foorn, F.G.S., Deputy Superintendent, 
Geological Survey of India. Journal of the Madras Literary 
Society, 1882. 
LTHOUGH there is still a vast field for geological investigation in 
India, much has already been done by the energetic labours of the 
members of the staff, considering the dangers, discomforts, and many 
disadvantages to which they are exposed, the results of which are 
embodied in the numerous records and memoirs published. The above 
paper is by the author of the excellent notice of the ‘Manual of the 
Geology of India’ which our readers may remember appeared in this 
Macaztne (1880, Vol. VII. pp. 79 and 127). 
Mr. Foote has given a brief sketch of the work done by the members 
of the Geological Survey in Southern India, and draws attention to 
the more important points of interest, whether practical or purely 
scientific, concerning the several geological formations met with. In 
this respect his long experience and personal knowledge of many points, 
and the full justice he has done to the excellent work of his colleagues, 
renders this notice extremely valuable as far as the South of India is 
concerned; and this is no contemptible work, for it appears that the 
area mapped, which lies chiefly on the eastern side of the Peninsula, 
amounts as nearly as possible to 100,000 square miles. 
The Cretaceous are by far the most interesting group in the country, 
with their great wealth of organic remains and the correlation with 
their presumed representatives in Europe, of which a table is given. 
The coast alluvium of the Madras district and the evidences of consider- 
able elevation of land in recent times is an interesting feature. The 
gneiss country offers some points of interest, specially the presence of 
many beds of magnetic iron, and also the building stones. These latter 
rocks have furnished the bulk of the stone used in building all the 
createst temples in South India. The position of the ‘‘ Diamond Sand- 
stones”’ in the Kadapa and Karnul districts and the labours of Messrs. 
Oldham and King are noticed. The stratigraphy of this great series of 
sub-metamorphic or transition rocks, which contain the Diamond sand- 
stone, had not been fully established until Mr. W. King, who worked 
out the greater part of these areas, recognized two distinct groups, an 
important advance in South Indian geology ; the two groups to which 
he gave the names Karnul and Kadapa are unconformable to each 
other, the basal conglomerate of the former containing the Diamond 
sandstone. Besides the Diamond rocks, useful limestones occur largely 
throughout the Karnul group; some of them have been utilized ; others, 
as the Palnad limestones, have of late been neglected, though many 
beds would furnish marbles of various colours and of great beauty. 
Their eminent suitability for decorative purposes had been fully ap- 
preciated by the old Buddhists, who built the exquisite carved railings 
and gateways to the great ‘“‘Tope’’ at Amaravati. Very interesting 
geological facts were gathered in the Madras region with reference to 
the gneissic rocks and their net-work of trap-dykes,—the plant- 
