24 BLANFORD : GEOLOGY OF WESTERN SIND. 



locally known as ' pat ' j it is highly fertile when irrigated, but is usually 



barren for want of water. The surface consists 



" Pat " 



of a fine light-coloured loam deposited by streams 



running from the hills. At the base of the hills themselves there is a 



slope of gravel corresponding to the Bhabar at the base of the Himalayas, 



and composed of detritus washed by water from the surface of the rocks : 



this slope frequently attains large dimensions. 



The southern portion of the Indus plain consists of the delta, the 

 head of which is generally placed a little above 

 Hyderabad, where the Falaili (Fuleli or Phuleli) 

 Channel leaves the main stream. The tide ascends the river almost 

 as far as Tatta, or 60 miles from the sea in a direct line. The portion 

 of the delta near the sea, extending 20 miles from the coast, is very 

 low, and it is flooded when the river is at its greatest height in the 

 monsoon, large tracts being overflowed at every spring tide. 



Within the area of the Indus plain, and even within the limits of 

 isolated hills in Indus t ,ne delta, there are some isolated tracts of low 

 P lain - limestone hills. The most northern of these ex- 



tends from the neighbourhood of Sukkur to the southward for nearly 

 50 miles, and is 17 miles broad where widest, near Kot Deji or Diji. It 

 rises about 150 feet from the plain in the neighbourhood of the Indus. 

 East of the Indus, in Lower Sind, there is a second smaller area of low 

 hills, on the northern portion of which the town of Hyderabad is built. 

 This tract of hills extends 21 miles from north to south, by about 6 miles 

 wide. A third ridge of high ground occurs close to Tatta, and is 18 

 miles long from north to south, and 4 from east to west. In all these 

 cases portions are detached and separated by alluvium from the main 

 rano-e, and there are some other small and unimportant patches, none of 

 which are of any size, near the edge of the alluvial area. One of these, 

 near Jhirak, is situated on the east bank of the Indus. 



The rock area near Sukkur is chiefly remarkable for being intersected by 

 the channel of the river Indus, which, strange to say, has cut its way 

 through the limestone range between the towns of Sukkur and Rohri^ 

 ( 2i ) 



