Mr. Winch on the Geology of the Banks of the Tweed. 1^1 



vegetables, but for an accurate description of these interesting Fossils 

 the pamphlet before mentioned must be referred to. At no great dis- 

 tance east of this escarpment a quarry has been opened on the side 

 of the bank to the depth of twenty feet, and is situated more than twen- 

 ty feet above the river. The stone here has a slight tinge of red, similar 

 to the stratum in the upper part of the cliff at Firebourn, which abuts 

 against the calcareous beds. It dips to the southward, and is divided 

 by thin slaty micaceous partings, and capped by about ten feet of loose 

 Sand, the abode of flights of Sand Martins. On the north side of the 

 Tweed, at the distance of a mile above Twizell Ferry, rocks of well- 

 defined Red Sandstone make their appearance. It is fine-grained in 

 texture, of a dark reddish-brown colour, and abounds with spangles of 

 silvery Mica. The cliff is of considerable elevation, and from hence to 

 the sea coast, thick beds of Red and Variegated Sandstone, at some 

 places covered by the thin calcareous strata previously mentioned, and at 

 others interstratified with them, become prevalent, though Coal Mea- 

 sures may be noticed in their vicinity (see Map, No. 8). On descend- 

 ing the river until opposite Twizell Boat House, fine-grained micaceous 

 Red Sandstone rocks, and those of the Coal formation, or at least such 

 as have heretofore been considered exclusively as such, are in close 

 contact. On the north shore, low rocks of the latter description appear 

 in situ, and, it may be worth remarking, that, on ascending the river 

 Till, for the distance of a mile westward, Twizell Castle (see Map, No- 

 9.) may be seen, built on an extremely hard grey micaceous Sandstone, 

 filled with Coal Scars* and so promising did this neighbourhood ap- 

 pear, as to induce the proprietor to make a trial for Coal. Three-quar- 

 ters of a mile further up the Till, the red rocks are again met with, 

 and worked at Mill Quarry, but at Dunstan Haugh, two miles and a half 

 from the castle, the stratum quarried is yellowish- white, and seemed to 



* Minute fragments of red Garnets are embedded in this Sandstone ; a circumstance I 

 have never noticed in the Sandstones of the Newcastle Coal-field, but in the Millstone grit 

 at Shaftoe Crags, near Wallington, the same mineral was detected by W. C. Trevelyan, 

 Esq., and it abounds in the Grauwacke of Bournmouth, north of Berwick. The Twizell 

 Sandstone I suspect to be an old member of the Carboniferous Limestone formation. 



