1866.] FISHER WARP. 563 



carried across Alresford Creek. The first cylinder was sunk in the 

 marsh, the second at the edge of the tideway. The sections given 

 to me were ; — 



First Cylinder. 



ft. in. 



Estnarine mud 8 



Black gravelly mud with shells 6 



" Yellow virgin soil," i.e. " warp " 3 



Second Cylinder. 



Estuarine mud 8 



Black gravelly mud with shells 6 



" Yellow virgin soil," ^. e. " warp " 3 



" Bluish-yellow clay," probably weathered 1 g q 



London Clay J 



I examined the materials thrown out of these cylinders, and they 

 agreed perfectly with the descriptions given to me by the foreman of 

 the^works. The warp was met with as far as the fourth cylinder — that 

 is, about 200 yards from the edge of the marsh. These facts prove 

 that the warp was formed before the last depression of the land ; for 

 the tide rises 10 or 11 feet above its surface. It may have extended 

 to a greater depth below high water than this ; for it is quite possible 

 that the reason of its not occurring in the middle of the tideway may 

 be, that it has been denuded. 



I met with another proof of the antiquity of the warp, of a differ- 

 ent kind, but of a similar significance, on the same line of railway. 



Fig. 11. — Section showing Warp cut offhy erosion of a stream. 



a y^^^^^^^^^^ ^'^^^^^^^^'^^^v Stream. 



a. Warp. b. Eecent sdt. 



Just west of Great Bentley, where on the map stands the letter 

 " s " in the word '^ millions," the railway crosses a valley. The 

 small stream which it contains has deepened the original valley by 

 about 12 feet, leaving a bank on the western side. A section of this 

 bank was visible in a freshly cut ditch on the north side of the rail- 

 way ; and it was noticeable that the warp was cut off at that point. 

 The soil of the recent flat bottom was a silt without any true warp 

 upon it. 



I believe it will turn out that the true warp, with its line of 

 pebbles at its base, does not extend over alluvial flats*, but (unless 

 it happens to have been denuded) passes beneath the recent 

 deposits. In short, it accompanies the original surfaces of denu- 

 dation. 



* No true warp was seen where the culvert was put in between Alresford and 

 Frating. 



