Geological Society. 1 09 



The tertiary deposit consists of a hard, argillaceous grit Covered b y 

 a conglomerate. The organic remains, which are very numerous, are 

 often disposed in beds confined to one species ; the prevaling gen era 

 being Area, Pecten, Ostrea, Cardium, Conus, Cypraea, Ovula, Fus us, 

 Trochus, Solarium, Strombus, and Cassis. Patches of Corals, two or 

 three acres in extent, sometimes also occur. 



Under the head of alluvial tracts, Capt. Grant gave an account 

 of changes, produced along the southern coast by the deposition of 

 sediment. At Mandavee is a ruin, at a spot called the old Bun- 

 der or quay, now about three miles inland j and in the centre of 

 the town is a small temple, built upon a rocky foundation, but said to 

 have stood in the sea when the old Bunder was the landing place. 

 At other localities in the Gulf of Cutch, similar processes are going 

 on, rendering it necessary to remove the landing-places frequently 

 further seaward. The rapid progress of these accumulations is 

 ascribed to the sea, during nine months washing back the sandy 

 detritus, brought down by the periodical floods. The same ope- 

 ration is also in progress at places separated from the main waters 

 of the gulf by small creeks or inlets, some of which penetrate six 

 or seven miles from the coast, through a tract covered with shrubs. 

 At low-water the whole of these plants are exposed down to their 

 roots, but at high tide merely their tops are visible, so that boats 

 sail through a completely marine forest. The growth of these shrubs 

 is rapid, and the sailors have, constantly to force the boats through 

 the upper branches, particularly at the angles of the creeks, when 

 they wish to save a tack. The stems and lower branches are 

 covered with testacea, whilst the upper are occupied by numerous 

 water-fowl. The land gains in this dictrict, by the deposition of 

 the muddy contents of the small streams during the monsoon, when 

 the water passing very slowly between the stems of the shrubs, a great 

 portion of the matter held in suspension, is precipitated. This alluvial 

 district occurs only on the southern coast of the Province. In August, 

 1834, the rains were very violent and continuous, and the river which 

 flows past Nurra, on the borders of the Grand Runn, covered with a 

 fine soil a surface of nearly 1000 acres. On the opposite or southern 

 side of Cutch, not far from Mandavee, 300 acres were washed away ; 

 and not far from the same spot, half a small village was removed bodily 

 into the sea. 



Volcanic Rocks. — Besides the southern range of hills already stated 

 to be entirely composed of trap or volcanic rocks, other extensive di- 

 stricts of the same nature occur between the northern and central 

 ranges, and to the south of Luckput ; besides innumerable minor 

 outbursts, some of which forming small conical hills, are arranged 

 around a central area. The author noticed no recent crater, unless 

 the hill, called Denudar, be considered as such, and down the flanks 

 of which he traced a lava stream. The volcanic rocks consist of 

 several varieties of basalt, often columnar, amygdaloid, green- 

 stone, and trachyte. Capt. Grant described these rocks in great 

 detail, as well as the effects evidently produced by them, enumerating 

 a great variety of instances, in which the disturbance of the strata can 



