102 



Geology of Bangalore^ and of 



[Jan. 



commencing at the gate going out of the pettah and near the fort. 



A very short way after leaving this gate, a trap or greenstone dyke is 

 ?een close to the road on the left-hand side running for many miles to the 

 westward— it here contains a good deal of felspar, and has numerous 

 needle-shaped crystals of a white colour — this dyke cuts through granite 

 containing very little mica, and is continued on for several miles. About 

 two miles from the pettah gate, it is seen rising into two or three small 

 hills on the left and close to the road. Here the trap assumes a basaltic 

 appearance, and a regular dyke of basalt is observed passing through a 

 granitic mass which lies between the trap rocks and the road, distant 

 from the last about sixty-five paces. I here found a piece of micaceous 

 iron ore. Some rather high granitic rocks are seen on the other side of 

 the trap dyke, forming one end of a large bund which is worth inspect- 

 ing, and which has been cut through — the masses of granite heaped to - 

 gether in a most confused manner. But resuming the trap dyke, which, 

 as j ust observed, here forms two hillocks, it now passes to the other 

 side of the Kingaree road, and extends as far as the eye can reach, form- 

 ing slight elevations. On the other side of the road, and near it, there 

 is a gneiss rock through which a vein of basalt passes, and from this 

 rock a very extensive view is afforded. The trap dyke is seen on the left, 

 near the road, and another is observed to the right, and they both run 

 along for many miles. The one on the right of the gneiss rock is not so 

 broad, but is in large tabular masses, not in rounded blocks, and ap- 

 proaches to regular basalt— a ravine between the two shows beds of 

 pegmatite and of hornblende slate. 



The region now under description is quite igneous, the speci- 

 mens of trap varying in appearance, but more or less either regular 

 basalt or basaltic trap. From, this gneiss rock, the trap dyke, be- 

 fore described previous to coming upon the Severndroog road, is also 

 seen. On returning to the main road, and passing through a 

 small tope, the road continues along, leaving the first described 

 trap dyke which stretches out to the west, the direction of the road 

 being now about south-west. A quarter of a mile on, a basaltic dyke 

 traverses the road east and west, the stratification of the rock through 

 which it cuts being north and south — the breadth of this dyke about one 

 foot, two inches. Continuing along this road for some way, a small 

 stream is crossed, granite and gneiss rocks on each side — further on an- 

 other small stream is passed, and now we find hornblende slate very com- 

 mon. Tnrning to the left, and following this stream on our way back, 

 large masses of hornblende slate are exposed in the bed of the stream, 

 and near this we come upon a rather high range of granite hills run- 

 ning norfh and south— the highest in the immediate neighbourhood of 



