There is an account (woefully out-of-date, no doubt) of this SSSI site in:
Treagus, J.E. (ed.) (1992) Caledonian Structures in Britain: south of the Midland Valley, Geological Conservation Review Series, No. 3, Chapman and Hall, London, 177 pp.
see chapter 2 (Southern Uplands) pp17-19. It maybe in your library and there are copies available on Amazon.
