262 



N ANNANDALE. 



near the north-east corner, is everywhere concealed, the land slopes gently towards 

 the water and the shore is occupied by a sandy beach. 



Throughout the interior of the island, the rock is concealed by a thin covering 

 of red soil which, nevertheless, is full of fragments of a material similar to that seen 

 where the rock is exposed in situ. Moreover the same rocks invariably re-appear 

 wherever the soil has been removed by artificial excavations. 



The geological constitution is very uniform. The whole island appears to be 

 built of stratified rocks, consisting of garnet-bearing quartzites with or without silli- 

 manite, as has been ascertained microscopically by Dr. Pascoe. The strike of the 

 bedding is uniformly east by about io° north, the dip northerly at low angles. The 

 amount of dip observed along the banks of an artificial pond about the centre of the 

 island is between 15° to 20.° Usually the angles are even lower. They are 



Text-fig. i. — Rocks at the north-west corner of the island. 



generally less than 10° along the east coast. Similarly low angles were observed at 

 the western corner of the island. Local undulations may occasionally cause the 

 lie to becoming horizontal, or ma}^ even bring about a temporary reversal of the dip 

 towards a southerly direction. An instance may be observed on the south coast 

 east of the landing pier. Sharp contortions are observed occasionally, for instance 

 at the north-east corner of the island, and, to a minor extent, at its western 

 extremity. 



The rocks clearly consist of altered sedimentary formations. They are refer- 

 able to T. L. Walker's ' khondalite series' and belong to the older division of the 

 'Transition rocks of Peninsular India.' 



The rock of the whole island has a very uniform appearance. In ordinary cir- 

 cumstances its surface is of a dull yellowish colour, often tinged with ferruginous 

 brown. Though hard it is coarsely granular. On weathering it breaks up into 



