120 Mr. WiNCB on the Geology of the Banks of the Tweed. 



The town of C oldstream (see Map, No. 6.) stands on what are usually 

 called Coal Measuj-es, comprising Sandstones and bituminous Shales, 

 exactly the same as those of the Newcastle Coal-field, and wherever Di- 

 luvium does not form the shores of the river, these may be traced for 

 the distance of two miles and a half. The little river Leat, which here 

 empties itself into the Tweed, passes through Mill Haugh, where the 

 late Lord Home bored for Coal, but to what depth I could not ascer- 

 tain. An extensive Free-stone quarry is worked in this field to the 

 depth of thirty feet j the upper and middle beds are white Micaceous 

 Sandstone, fine-grained, and full of Coal pipes, the lower is free from 

 these vegetable exuvi^.* A strong chalybeate spring rises to the day, 

 and runs into the Leat at a short distance from the quarry. Both above 

 and below Coldstream Bridge the Tweed flows over these Coal Measures, 

 which dip, at a trifling angle, to the south-east, and the rocks on the 

 south side having been cut through. Micaceous Sandstone, alternating 

 with Bituminous Shale, and covered with a bank of red earth, are laid open 

 to view, and beds of the same nature may be noticed half a mile lower 

 down the stream. But the cliff at Lennel Braes (see Map, No. 7-)> on 

 the north side, two miles to the eastward, exhibits the most perfect sec- 

 tion of this suite of strata to be met with in the vicinity. At the Braes 

 the perpendicular cliff extends for more than a hundred yards, and was 

 estimated by me at forty feet in height, exclusive of its diluvial cover- 

 ing, but the correct section, published in Mr. Witham's pamphlet 

 On the vegetable Fossils found there, makes its elevation forty-four 

 feet. The uppermost bed is Sandstone, which is succeeded by four others, 

 alternating with slaty Sandstones, or Coal Metals and Shales enclosing 

 balls of Clay L-on-stone. Their dip is north-east, and the rocks on the 

 south side of the river appear to resemble them. The petrified trunks 

 of trees are irregularly dispersed through the lower bed of Shale, and 

 are both of the Monocotyledonous and Dicotyledonous classes of 



* Sandstones, bearing strong indications of being associated with beds of Coal, are quar- 

 ried at Sprouston, in Roxburghshire, for an account of which see Mr. Buddle's pamphlet 

 " On the search for Coalin a part of the counties of Roxburgh and Berwickshires, in 1806," 

 pp. 10, 11. These Sandstones are very hard, and filled with Coal pipes. 



