RECENT DEPOSITS. 37 



CHAPTER V.— RECENT DEPOSITS. 



I. Blown sand. 



The most widespread and important of the recent formations of 

 Western Kajputana is undoubtedly the blown sand with which so 

 large a portion of the country is covered. Driven by the south- 

 westerly gales which blow across the desert for several months in the 

 year, and unimpeded in its advance by streams of running water, it 

 has encroached upon the land until no district is entirely free from 

 it, except those lying immediately at the foot of the Aravalli range, 

 where the numberless watercourses descending from the hills, 

 although they contain running water for only short periods, are able 

 to sweep back the sand blown into them. 



The dunes that are formed in the open plain are all of the trans- 

 verse type, that is, they present a broad gently sloping face to the 

 south-west, and a steep slope, corresponding with the angle of rest 

 of the sand, to the north-east. A plain covered with these sandhills, 

 such as that to the north-west of Pachpadra, presents a curious aspect 

 when viewed from the top of one of the rocky hills to the east, in the 

 evening, when the sun is sinking towards the western horizon. The 

 steep face of each sand dune casts an intensely black shadow, while 

 from the elevation on which one is standing the lower ground appears 

 as a uniform level, so that the country presents the appearance of a 

 yellow plain crossed by a number of black bars, parallel to each other, 

 the cause of which is not at the first glance very evident. 



Where, as is often the case, the sandhills are formed under the 

 lee of one of the rocky knolls, they form long ridges extending in a. 

 north-east direction. The sand is also banked up against the wind- 

 ward side of the hills, and sometimes rises to a great height, over 800 

 feet in the case of those at the western end of the Saora range, above the 

 plain. But as a rule they do not actually reach the slopes of the hills, 



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