Page:Transactions of the Natural History Society of Northumberland, Durham, and Newcastle-upon-Tyne (1867).djvu/19

Rh

Cambro-Silurian strata occupy but a small area in the western part of Northumberland, and do not occur in Durham. They are highly inclined against the porphyry, in the bed of the Coquet a little above Philip, and extend beyond the source of that river into Scotland. In a deep ravine, eastward of Makendon, they are well exposed ; and the Roman camp at Chew Green is formed out of them ; for some of the rampiers are natural walls of Greywacke in situ, the rock having been removed on both sides.