112 BLANFORD : GEOLOGY OF WESTERN SIND. 



the main valley, between ridges of lower Nari and Khirthar beds, and 

 the level, or nearly level surface of the hollow, for 



Extensive deposits of j- , n ,, • • , . . , 



calcareous tufa. some distance trom the spring, consists entirely 



of calcareous tufa, which terminates in a cliff, 200 

 feet high (by Aneroid), and several hundred yards in length. The water 

 from the spring descends this cliff in a raised channel, formed by the 

 deposit of tufa ; and older channels, each raised above the general surface, 

 may be traced here and there upon the face of the cliff. All these fea- 

 tures were well described by Vicary, l who visited this place in 1845. 



There can be no reasonable doubt that the enormous mass of calcare- 

 ous tufa seen has been deposited by the present spring. But on the 

 surrounding hills there are other masses of tufa, at a higher level than 

 the spring. These probably mark ancient points of issue. 



A large stream, the Naegh Nai, runs from the south past Pir 

 Gazi. The valley of this stream, although chiefly 

 composed of Nari beds, does not consist of 

 them so exclusively as the Angyi valley does. In the first place allu- 

 vium extends up the valley for a long distance, and should perhaps be 

 shown farther to the southward than is indicated on the map. In the 

 northern part of the valley, near Pir Gazi, the alluvial ground is con- 

 tained in a deep synclinal fold of the Manchhar beds, steeper on one 

 side than the other, the dip being 50° to 60° west of the valley and 

 35° to 40 c to the eastward ; but farther up the valley alluvium rests 

 upon both Gaj and Nari beds. 



The Gaj outcrop crosses the valley about 7 or 8 miles above 

 Pir Gazi, the actual crossing being concealed by 

 alluvium. Hence to the eastward the direction of 

 the strike of the main Gaj outcrop is east by south. At Shah Ruhi 

 (Gulam Shah), about 13 miles from Pir Gazi, there is a slight anticlinal 

 roll in the middle of the valley and the lower Nari beds ; the yellow 

 limestones with Nummulites and Orbitoides are brought to the surface, but 

 farther up the valley southerly and westerly dips bring in higher beds. 



1 Qunrt. Jour. Geol. Soc, 1847, p. 344. 

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