470 Geology of 



the same well was sunk to 166 feet the water gained 9 feet in height. 

 The numerous borings all over Christchurch and its neighbourhood 

 have given us a clear insight into the nature of the deposits by which 

 the Lake Ellesmere extension was filled up. The bottom of the 

 water-bearing stratum consists invariably of a bed of shingle, mostly 

 •of small size, upon which a deposit of sandy clay reposes. Above this 

 the character of the beds changes incessantly, and often within very 

 short distances from each other. 



In some places the deltaic deposits of rivers reach from near the 

 surface to the water-bearing stratum, as for instance, in Upper Eiccarton, 

 where after passing through 76 feet of shingle, water is obtained. It 

 rises however, only within six feet of the surface. Near the foot of 

 Banks' Peninsula, near "Walthain, the shingle continues for about 

 100 feet till water is reached. At Middle Eiccarton the shingle begins 

 at only 50 to 60 feet below the surface. 



In some parts of the district deposits of shingle are only near the 

 surface, as in Cathedral square, and in Cashel street west, in others it 

 forms only the central portion of the deposits passed through. Thus 

 in Armagh and Chester streets east, shingle begins at 27 to 33 feet 

 below the surface, continuing for about four feet, when it is underlaid 

 by sandy deposits continuing to the bottom, about 98 feet. 

 In some other portions of the city, as for instance in Hereford street 

 east, there are deposits of silt, peat and sand for about 33 feet, after 

 which the remaining 60 to 65 feet are formed by well cemented shingle, 

 before the water is reached. In other places again, only sands, greyish, 

 yellowish, or blackish, with occasional deposits of peat, driftwood, and 

 silt have been passed by the well-borer. AV r e have also good evidence 

 of the character of the deposits in the Lower Heathcote district, in a 

 brick well sunk a few years ago for obtaining a water supply for 

 Lyttelton, and of which the details were kindly furnished by Mr. H. B. 

 Huddleston C.E. This well reaches a depth of 40 feet, the whole 

 consisting of sandy silt, such as is now being formed in the estuary 

 of the Heathcote. At depths of 6| and 25 feet from the surface, two 

 layers of Estuary shells were passed through, each about six inches in 

 thickness, consisting mostly of specimens of Chione StucJiburyi and 

 Amphibola avellana, still now living in the Heathcote estuary. Also 

 a great deal of driftwood was 'met with. 



To give a few more examples, I shall here offer the details of two 

 artesian wells sunk to the east of Christchurch, in order to show the 



