Mr. Winch on the Geology of the Banks of the Tweed. 123 



micaceous Sandstone abound, and greatly impede the work of the 

 quarry-men j some of these nodules are not many inches in diameter, 

 but I measured one of two and a half feet ; they are not ranged in lines, 

 but their sharper extremities point towards the north-west, which is the 

 full rise of the stratum containing them. Proceeding eastward to the 

 vicinity of HornclifFe House, the rocks are still Red Sandstone, with si- 

 milar calcareous seams as those near Norham resting upon them, and a 

 cut, made to widen the road to the Chain Bridge (^see Map, No. 14.), lays 

 open thirty feet of rock, comprising six different strata ; the lowest is 

 Red Sandstone, the others Limestone and slaty indurated Marl. A slip 

 of six feet cuts through these beds. Above West Ord (see Map, No. 15.), 

 a cliff of sixty feet again exhibits the nature of the rocks ; here the Va- 

 riegated Sandstone rests upon the red, which is filled with nodules of 

 Red Ochre, and is covered by the calcareous series so frequently 

 mentioned ; and at the plantations, a httle lower down the river, six alter- 

 nations of these thin beds are covered by thick strata of Red and Variega- 

 ted Sandstone. At Ord Mill, the red rock alone is visible ; the dip of the 

 whole series is southward of east. Diluvium now covers the rocks on the 

 south shore of the Tweed the whole way to the harbour, but on the north 

 bank, Berwick Castle {see Map, No. 16.) stands upon an elevation about 

 ninety feet high. Under the soil the rocks are Variegated and Red Sand- 

 stones, of extremely fine-grained texture ; the beds are thick, in which 

 they may be compared to the posts in this part of our district, while the 

 thin calcareous strata occupy the place of our Metals and bituminous 

 Shales ; but so considerable a proportion of Carbonate of Lime do all 

 the Sandstones hereabout contain, that they effervesce on the application 

 of diluted mineral acids. The dip southward of east. From the rocks on 

 which Berwick Castle is constructed, to the entrance of the harbour (see 

 Map, No. 17.), the space is covered by soil ; but both towards the north 

 and south high and rugged cliffs bound the ocean. Those to the north 

 shall first be brought under consideration. On passing through the Sally- 

 port, and before reaching the Pier, the following succession of rocks rise 

 to the day: — 1st, a thick stratum of fine-grained brick-red micaceous 

 Sandstone ; 2d, hair-brown Limestone, with small Encrinites ; Sd, 



