476 WELL-BORINGS ON THE INDIAN PLAIN. 



through sand and clay all the way. * Also at Umballa, 

 an important cantonment on the line from Delhi to 

 Simla, at an altitude of 905 feet above sea-level, and 

 twenty miles from the base of the mountains ; a depth 

 of 701 feet was here attained with practically a like 

 result ; that is to say, the borings passed through sand, 

 but, in this case mostly beds of clay, f 



The reader will here see the great thickness of these 

 apparently (according to the Encyclop. Britannicd) fresh 

 water beds; and the slow rate at which such are de- 

 posited, which (according to Mr. Richardson) does not 

 exceed about one foot per century, supplies a wonderful 

 piece of circumstantial evidence as to the great antiquity 

 of the earth, especially when we bear in mind that at 

 a still greater, but at present undetermined depth, be- 

 low these 'fresh water strata, we reach the tertiary rocks, 

 which are on the contrary full of marine remains, show- 

 ing that before the great lake (if there was one) the 

 ancient sea had rolled for uncounted ages above the 

 Indian plain. Now, these tertiary rocks are in all pro- 

 bability some thousands of feet in thickness, and they 

 were deposited by this sea at a rate which according to 

 competent geologists, little, if at all, exceeds the rate 

 of accumulation from fresh water deposits, as stated 

 above. But inasmuch as these strata have been sub- 

 jected to enormous pressure, it follows that one foot 

 (of chalk, for instance) would represent a vastly greater 



* See Mamial of the Geology of India, compiled from observations of 

 the Geological Survey Department, by H. B. Medlicott, Superintendent 

 of that department, and W. T. Blandford, F.R.S.; Calcutta, 1879. 

 Part i., Chap, xvii., p. 399. 



j- Ibid., Chap, xviii., p. 401. (NB. At the pages indicated a com- 

 plete list of the various beds, their thickness, nature, colour, etc., are 

 all specifically stated). 



See Richardson's Geology and its Associate Sciences, 2nd edit., p. 86. 



