DISTURBANCES AND FAULTS 247 



described as replacing one another along a line ranging a little 

 north of east. It is therefore in accordance with this rule that the 

 Sandown anticline lies a little to the north, as well as to the 

 east, of that of Brixton, and that the one dies out where the other 

 begins. The actual region in which this replacement of the one 

 fold by the other takes place lies between Calbourne and Gat- 

 combe. For west of the longitude of Gatcombe the Sandown 

 anticline gradually flattens out, so as to allow the Chalk to 

 extend itself southwards, but at the same time the extreme 

 southerly point of the spread of Chalk, v'vz., Chillerton Down, 

 assumes a dip which is obviously due to the Brixton anticline. 

 The increase in this dip along the southern border of the Downs 

 proceeds pari passu with the flattening of the Sandown anticline 

 along the northern border, until at Calbourne the latter is scarcely 

 recognisable, while the former has become fully pronounced. 

 Between these two lines, viz., about Newbarn, Rowborough, and 

 Idlecombe the beds are nearly horizontal, but nssurae a westerly 

 dip further west, which increases to 1 7° near Calbourne 



