1836.] the Country between Hyderabad and Ndgpur. 101 



granite, was in others more loosely connected, and easily separated by 

 the progress of decomposition, leaving rounded cavities in the rock. 



A circumstance of more importance, however, is the occurrence of 

 the beds of kankar in this tract, being, as far as I have observed, al- 

 ways near some of the greenstone dykes or beds, and frequently under 

 or intermingled with masses of granite, which is in a rapid state of 

 decay : these are usually rounded, partly from the progress of decom- 

 position, and sometimes from the tendency to concentric forms, which 

 it occasionally undoubtedly assumes. The small detritus is in some 

 places accumulated to a great depth, and it has been stated by Dr. 

 Christie, that this debris is, at a considerable depth, again consoli- 

 dated by pressure. In the Edinburgh Journal of Science, 1828-29, this 

 is also mentioned as a fact, common to the rocks of other parts of 

 India. With every respect for his authority, I cannot avoid the con- 

 viction, that the inference was founded on imperfect observation, and 

 that it has since been employed in Europe, in support of an ill-founded 

 theory. 



No. 15, is " Mhurrum" or gravel found in deepening a well at 

 Bolaram, (six miles from Secunderabad,) upwards of 50 feet deep, 

 during the very dry season of 1832, and is not in the slightest degree 

 consolidated. A loose block, which had resisted decomposition, was 

 found above it, and contains mica, (No. 15,) a rare ingredient in the 

 granite of Hyderabad. Much of the dsbris at Sacunderabad is, how- 

 ever, consolidated by lime, which is seen to agglutinate the fragments, 

 or to pass in vein-like lines or nodules through the gravel. Occa- 

 sionally there are only a few fragments of quartz or felspar scattered 

 through the kankar, or they appear to be inserted into the surface, as 

 in No. 10, which is extremely hard. Generally, however, the agglu- 

 tinated gravel is friable, and the cement less obvious. The debris is 

 also sometimes united into pulverulent masses, by the oxidation of the 

 iron contained in the sienite ; b\it this takes place at the surface, and 

 seldom acquires any great degree of hardness. Specimens of the 

 granite in the neighbourhood of Hyderabad are numbered 14; and 

 the appearance of the surface of that polished by the continual passage 

 of hyenas, in the entrance of the caverns formed in the pile of gneiss 

 or granite of the " Chita hill," near the cantonment, has been 

 described in the 1st volume of the Journal of the Asiatic Society, (No. 

 12.) The greenstone occasionally has distinct crystals of felspar 

 scattered through it, without the porphyry thus formed, losing the 

 remarkable degree of toughness possessed by the black rock ; but, as 

 observed by Sir H. Davy, the decomposition of the felspar is more 

 rapid than of the other parts, (No. 19.) The greenstone is familiarly 



