122 Mr. Winch on the Geology of the Banks of the Tweed. 



be a Coal Sandstone. But to return to Tweed side. On the south 

 bank, above the Ferry House, there is a perpendicular cliff, forty feet 

 high, of white Sandstones, though tinged red on their surfaces by the 

 oxidation of their Mica ; the beds are separated by thin micaceous part- 

 ings, and in every respect resemble the rock quarried below Lennel. 

 On the north side, just below the ferry, the cliff is not less than fifty 

 feet above the stream, and composed of fine-grained Red Sandstone, with 

 small scales of silvery Mica. On descending the river, the rocks on 

 the south shore continue red, micaceous partings divide the thick strata, 

 through which nodules of Red Ochre are dispersed in abundance, and 

 those on the north side agree with them in every character. 



Opposite Newbiggin (see Map, No. 10.), the elevated cliffs are rendered 

 singular by an escarpment of bright red Marl, which, from a distance, 

 is a striking object. The dip is towards the south-east. Near Norham 

 Boat House (see Map, No. 11.), the Tweed sweeps round the foot of a 

 promontory of not less than seventy to eighty feet in height ; its rocks 

 are red, and differ in no respect from those a little higher up on the 

 north bank of the river. To the eastward (see Map Nos. 12 and 13.), 

 Norham Castle stands upon an eminence overlooking the Tweed, and, 

 as the stones of which it is constructed are red and white, the vicinity 

 of quarries of both these kind of rock is evident, but the geology of 

 its immediate neighbourhood may be studied to most advantage by 

 carefully inspecting the abrupt cliffs below the castle mount. A 

 beautiful and interesting section is there developed. The lowest bed, 

 which is scarcely above the level of the stream, consists of a whitish 

 Sandstone and Limestone forming a Breccia ; on this rests a stratum 

 of reddish Sandstone, forty feet thick, vi'hich is, in turn, capped by four- 

 teen thin seams of soft ash-coloured Limestone, interstratified with an 

 equal number of others of greenish-grey slaty Marl, mixed with sand 

 and silvery Mica ; their aggregate thickness is twenty-five feet, which, 

 with five feet of Diluvium, will give seventy feet as the elevation of the 

 escarpment. When viewed from below, the upper part of this singular 

 cliff appears to be striped with the regularity of a ribbon. In the 

 thick bed of Sandstone, pear-shaped nodules of extremely hard white 



