1840.] 



On the Geology of Cutch. 



311 



5. Nummulitic limestone and marl. 



6. Tertiary strata. 



7. Alluvial, or recent deposits. 



S. Volcanic and trappean rocks, including all such as bear evident 

 marks of a perfectly igneous origin, as basalt, &c. 



These eight divisions, considering the red sandstone as one, represent 

 generally the geological structure of the province, though many minor 

 subdivisions might doubtlessly be made. 



1. Syenite and Quartz Rock. 



The only good example of syenite eri masse is a hill called Calunja, 

 near the town of Nuggur in Parkur, a district in the Thur, and not far 

 from the mouth of the Loonee river. It is not in Cutch Proper ; but as 

 it forms part of the northern coast of the Runn, and is in other respects 

 connected with the geology of the province, I have introduced it as one 

 of the formations. 



The Calunja hill is a confused heap of light red syenit.ic rocks, com- 

 posed of quartz, red or white felspar, and large long crystals of horn» 

 blende ; the compound being sometimes coarsely grained, and some- 

 times finely. The base of the main hill is surrounded with small conical 

 mounds, which, at a distance, resemble the huts of a village. On enter- 

 ing the space occupied by these mounds, the hill presents a number of 

 irregular, shattered masses, the sides oi which are so steep, and are worn 

 so smooth by the action of the elements, as to be extremely difficult of 

 access. Between these masses the sand lies very deep. If is quite evi- 

 dent, that this hill has been violently acted upon by earthquakes. 



In the bed of a river near the village of Koonerea, in the Puchum is- 

 land, situated in the Grand Runn, I found some masses of precisely 

 similar syenite, which were probably erratic blocks from the Calunja 

 hill ; this island lies nearly in the direction which would be taken by any 

 sudden floods, coming down the Loonee river. 



Quartz Hock. — This rock is principally developed in a hill of consider- 

 able height ne^r the town of Mhurr, situated towards the western side 

 of the province. The upper part of the hill is entirely composed of it, 

 and huge masses are scattered about the base. A larg^ cleft extends 

 about halfway up the western face of the hill, and displays its internal 

 structure, consisting of a centre of quartz rock, surrounded by horizontal 

 strata of loose, quartzose sandstone. The quartz rock varies considera- 

 bly in character, being sometimes perfectly compact, exceedingly hard, 



