4 A NEW FLOEA OF 



Southward of the Coquet they extend for some distance along 

 Watling Street. They appear, too, in the bed of the Eeed, near 

 to Eamshope, and up the E.iver beyond White Lee, and up the 

 Carter Fell, by the road side, nearly as far as the toll bar. They 

 are a prolongation into Northumberland of the same formation, 

 which runs across Berwickshire, from Siccar Point in a west 

 south-west direction, and which occupies about one-third of Rox- 

 burghshire, with rolling hills of moderate elevation. In IN'orth- 

 umberland these rocks reach a height of 1700 feet above the sea 

 level, and consist of distinctly stratified Greywacke and Grey- 

 wacke Slate ; but though much jointed, and divided sometimes 

 into flat irregular prisms, they have no slaty cleavage. Crushed 

 and squeezed, highly inclined, and folding over each other, their 

 dip is irregular both as to direction and amount, yet the general 

 strike of the beds is, on the Coquet, from north-west to south- 

 east, and on the Eeed from west to east. Composed of felspar 

 and quartz, with a little mica and sometimes chlorite, their dis- 

 integration yields a soil retentive of moisture ; but as drainage is 

 eifected through numerous joints and the highly inclined planes 

 of stratification, the soil above them is comparatively dry. The 

 protusion amongst them of mighty masses of igneous felspathic 

 rocks, in the border counties, seems to me sufficient to account 

 for their elevated and crushed condition. 



Their position in the geologic series is thus far certain — ^they 

 are much older than the Old Eed Sandstone conglomerates, which 

 cover them unconformably in Berwickshire and Eoxburghshire ; 

 and on the Eeed they are in like manner overlaid by Mountain 

 Limestone beds. Fossils have not been detected in them in 

 Northumberland, nor in Eoxburghshire; but Mr. Stevenson, of 

 Dunse, has found a Graptolite and tracks of an annelid in Grey- 

 wacke, on the Dye Water, in the northern part of Berwickshire, 

 in beds, however, which appear to be high in the system. The 

 Northumberland strata may be of the same age as the Longmynd 

 rocks, referred by Sedgwick to the Cambrian, and by Murchison 

 to the Lower Silurian system ; and hence, until more definite 

 knowledge is obtained, they may conveniently be designated 

 Cambro- Silurian . 



