Chloritic Series or Upper greensand.
"The Student's Elements of Geology"
Sir Charles Lyell
4. There are sometimes different contiguous and parallel escarpments- those, for example, of the greensand and chalk- which are so near each other, and occasionally so similar in altitude, that we can not imagine any existing archipelago if converted into dry land to present a like outline.
"The Student's Elements of Geology"
Sir Charles Lyell
The above theory is by no means inconsistent with the opinion that the limits of the outcrop of the chalk and greensand which the escarpments now follow, were originally determined by marine denudation.
"The Student's Elements of Geology"
Sir Charles Lyell