54 LA TOUCHE: GEOLOGY OF WESTERN RAJFUTANA. 



sand. It is composed of quartz, pink felspar, mica, hornblende and 

 a briglit greenish yellow mineral, probably epidote ; it weathers into 

 rounded exfoliating masses and shows no traces of foliation, though 

 it is traversed by roughly parallel joints which give it a certain 

 appearance of being bedded Included in it are numerous rounded 

 patches of a darker coloured rock, measuring up to 6 inches in 

 diameter, some of which appear to be fragments of schist. They 

 are always more fine grained than the surrounding granite, but some 

 of them contain the same ingredients, with a larger proportion of 

 small crystals of mica or hornblende, which give them their darker 

 colour, and these may be concretionary in origin, being merely the 

 result of an abnormal arrangement of the constituents of the granite. 

 Exactly similar patches are described by Mr. J. Arthur Phillips, as 

 occurring in many of the granites of the United Kingdom, in a paper 

 ,l on Concretionary Patches and Fragments of other Rocks con- 

 tained in Granite," 1 where the author comes to the conclusion that 

 some are of concretionary origin, while others, generally schistose in 

 character, are foreign fragments derived from the rocks through 

 which the granite has forced its way. 



Seven miles to the east of Salawas, on the right bank of the Luni 

 river near the village of Rajpura, a large spread of Malani lavas 

 occurs, forming a low rise extending for some two miles along the 

 river bank. All the rocks exposed are lavas of different varieties, 

 some strongly porphyritic, and others exhibiting good flow-structure. 

 Mr. Hacket says that he found some very much decomposed olive 

 green schists in the bed of the Luni almost in contact with the lavas, 

 but that no junction between the two was exposed. These schists 

 were covered by the sand of the river at the time of my visit, and I 

 could not find them. 



Two small hills, both composed of rhyolites, occur isolated in the 

 plain a few miles to the south and south-west of Salawas. The 

 1 Quart Journ. Geol. Soc, Vol. XXXVI, p. i. 

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