206 



Notes on Geological Specimens from 



[July 



lying loose on the surface, and abounding in shells of various fa- 

 milies. Some in a green crystalline mass, resembling an ore of 

 copper, were in many instances converted into quartz crystals, re- 

 taining the perfect form of the shells ; one of these of exquisite 

 beauty, which has been unfortunately broken, was found in the interior 

 of a larger one : others were imbedded in a tough white clay rock, so 

 soft as to soil the fingers. The greatest part consisted of a siliceous 

 rock, partly converted into a black bituminous flint, or a coarse quartz, 

 partially altered into calcedony, into which the majority of the shells 

 were converted. Some, on the contrary, retained the structure of the 

 shell unaltered, and effervesced with acids. 



Amongst these, the fragments containing the fossil seeds of chara, 

 associated with fresh-water shells, were found. The gyrogonites were 

 not observed at the time the specimen was found, but the rock to 

 which it belonged could not be far distant, as the shells are of the 

 same species as in other specimens, having a similar mineralogical 

 structure. In other fragments, remains of grasses appearing half con^ 

 sumed were seen ; and in the large protruding mass of red chert, 

 containing shells converted into calcedony, I discovered what I take 

 to be the tooth of an herbivorous quadrupei. A few of the shells I 

 believe to be marine, and at the distance of half a mile, the principal 

 masses of grey chert, containing the large marine shells were found. 



On descending towards Thitnoor, granite is seen at one place, and 

 above, much quartz, having a slag-like surface of the kind seen above 

 Nirmul, occurs. A few specimens of black chert, with shells, were 

 picked up ki the bed of a nulla at Thitnoor, where it was also found 

 in situ. A loose piece of reddish and green flint, with shells, was also 

 met with in a ravine three miles further north. Much lime and kankar 

 was here mixed with the black soil, or was deposited in the water 

 courses ; the greater part probably derived from the decomposed basalt, 

 or from such layers of a soft white limestone, as were found between 

 the laminae of basalt, in digging pits to obtain water for the troops, 

 when encamped at Etchoda. A compact stratified limestone, however, 

 occurs in the vicinity. 



The pass from Thitnoor, called the Muklegandy ghat, is formed 

 of several terraces, of which three only are remarkable, and a steep 

 descent between each. The surface rock of the second terrace is a 

 rough, white limetone, which appears to be consolidated in nodules, 

 until it was broken, and found to consist of a great variety of shells, 

 many of great size, but difficult to remove entire, forming a rock of a 

 crystalline texture. The strata are horizontal, and in one place, where 

 it is cut through by a torrent, the rock is 12 feet thick, and is seen to 

 rest directly on granite of a reddish colour. The shells are of very vari- 

 ous forms : several belong to the genus Qstrea of Linnaeus j one very 



