44 LA TOUCHE : GEOLOGY OF WESTERN RAJPUTANA. 



CHAPTER VI.-DETAILED DESCRIPTIONS OF ROCKS. 



When the exposures of the rocks are so isolated from each other 

 as they are in Western Rajputana, the usual method of describing 

 their relations in detail, by following the belts of outcrops of the 

 various strata across the country, is hardly practicable, and I have 

 thought it more convenient to take each quarter sheet of the atlas of 

 India on the scale of 4 miles to the inch, covering the area surveyed, 

 separately, and describe the rocks found in it, noticing any points 

 worthy of remark in the sections exposed. 



i. Quarter sheet 19 S. E. 



The greater part of the area included in this quarter sheet is covered 

 by blown sand and alluvium. At the western edge about Lawa (Lowo) 

 the Talchir boulder beds are exposed, along the foot of a scarp of 

 Vindhyan sandstone. Several detached outcrops of the Vindhyans 

 occur between this place and Teuri near the south-east margin of the 

 map. They either just show above the surface of the ground between 

 the sandhills or rise into scarped hills and plateaus of no great height. 

 Several large groups of these hills occur in the neighbourhood of Osia, 

 about 12 miles north of Teuri. The sandstone scarps rise abruptly 

 to a height of 100 to 150 feet above the plain, and the base is always 

 concealed by sand. The peculiar striae-like markings described in 

 Chap. IV, p. 30, were found among these hills between one and two miles 

 south-east of Osia, near a small village named Basin, not marked on 

 the map. 



Several small inliers of the Malani rhyolites occur among the sand- 

 stones forming the plateau west of Bastua, near the southern edge of 

 this quarter sheet, and others are isolated among the sandhills near 

 Ketu, to the west of the same plateau. The largest of these inliers 

 occurs in a narrow gorge immediately above the southern village of 

 Bastua. The lava has the appearance of a ridge or hummock that has 

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