THE UNDERGROUND FORM OF FLOOR OF GANGETIO TROUGH. 83 



information. A list of the latitude stations, ranged in order of 

 their distance from the main boundary, is given in table 24, from 

 which it will be seen that there is first a northerly deflection, which 



Table 24. — Latitude Stations in the Punjab. 



Station. 



Approxi- 

 mate 

 distance 



Observed 



deflection 



in the 



Resulting 

 deflection 

 normal to 



Deflection 

 due to 



Remainder. 





from main 

 boundary. 



meridian. 



range. 



1 



range. 





Ranjitgarh 



30 



— 2 



_ 2 



— 



+ 3 



Isanpur .... 



50 











2 



+ 2 



Shahpur .... 



55 



+ 5 



+ 7 



— 2 



+ 9 



Amritsar .... 



85 



+ 8 



+ 12 





+ 12 



Sangatpur. 



90 



+ 5 



+ 7 





+ 7 



Rakhi .... 



110 



+ 3 



+ 5 





+ 5 



Khimuana 



120 



+ 1 



+ 1 





+ 1 



Sawaipur .... 



140 



+ 3 









Tasing 



190 



+ 4 









Ram Thai 



200 



+ 3 









Garinda . 



230 



+ 3 









becomes southerly with increasing distance, increases in amount 

 to a maximum at Amritsar, and then diminishes. This is exactly 

 the character of the change in the deflections noticed in the Gan- 

 getic trough, though there spread over a greater distance, and the 

 similarity is more striking if the stations of Sawaipur and the three 

 others following it are left out of count ; these, as will be seen by 

 reference to the map, are detached from the rest, and it is doubtful 

 whether the southerly deflections are due to the trough, or to some 

 cause independent of it, such as has been met with south of the 

 Gangetic trough, in the northern part of the Peninsular rock area. 

 To some such cause must be attributed the southerly deflections 

 at the last three stations in the list, which lie within the area map- 

 ped as alluvium, but in a region where geological observations 

 show that there is probably no great depth of alluvial cover on 

 the rock floor, and where it is difficult to believe that the southerly 

 deflections can be due to the effect of an alluvial trough. 



Omitting these, we have a fairly compact group of latitude 

 and gravity stations which deserve more detailed study, but before 

 this can be done it is necessary to convert the recorded deflections, 

 which were measured in the meridian, into the corresponding 



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