242 Geological Section from Nimach to Merta. [May, 



varieties composed entirely of quartz and felspar ; these two ingredi- 

 ents, being arranged in nearly parallel grains of a prismatic form, 

 the felspar frequently entirely surrounding the longish grains of 

 quartz, and giving rise to a porphyritic structure. The felspar is 

 the principal ingredient in these granitic rocks or perhaps granitic 

 gneisses. 



Q. The waved sienitic gneiss, similar to that described in a former 

 paper, as occurring at Kardbar. The country where this occurs is generally 

 covered with soil, but in one or two instances it presents itself at the 

 surface. S. Primitive dolomite; it occurs regularly stratified, the 

 surface where exposed, having acquired a dark earthy aspect, The 

 fresh fracture is coarse-grained and crystalline : some of the crystals being 

 of rather a darker color than others, and the whole being of a smoky 

 grey. It is almost entirely dissolved in nitric acid, and is composed of 

 carbonate of lime, with which a considerable proportion of carbonate of 

 magnesia is associated. This is succeeded by alternations of granitic 

 rocks, W. W. W., and hornblende l'ocks, X. X. X. The granitic rocks 

 of this series are very various, some are large-grained, and are composed 

 principally of flesh-red felspar and white quartz ; some are fine-grained ; 

 many of them almost compact, composed of similar ingredients but 

 are of a lighter colour. In both mica occasionally occurs, but in very 

 small quantity. It is sometimes dark-green and at others greenish yel- 

 low ; the quantity of mica varies much in different beds, and is very fre- 

 quently entirely wanting. Sometimes too a granite rock occurs, prin- 

 cipally composed of whitish or pale red granular felspar, to which quartz, 

 mica or chlorite are occasionally added in small proportion. In many 

 of the fine-grained granitic rocks, &c. minute yellowish green specks of 

 epidote are observed. Some additional remarks on the above rocks will 

 be found in my memoir. The hornblende rocks X. X. X. exist in the form 

 of a nearly pure hornblende rock, and to this last felspar of a grey color 

 is occasionally added. When quartz exists in any quantity in these, they 

 pass into sienitic granite. Hornblende schist is also common, and with 

 this a small proportion of felspar is occasionally associated, making it 

 sometimes appear to pass into sienitic gneiss. 



An idea of the form of the hills near the line of section may be ga- 

 thered from the slight uncoloured sketch placed over the different for- 

 mations. The line of section however does not traverse any of these. 

 The general dip of the strata is to the N. E. and after leaving Nakrtim 

 their position is nearly vertical. 



N. B. Merta is distant 12 miles from Oudaipur. It lies to the? 

 east, and a little to the north of the latter city. 



