﻿1850.] HARKNESS ON THE SILURIANS OF DUMFRIESSHIRE. 47 



friesshire with Peeblesshire, there are seen in a rivulet, running along 

 the south-western base of the hill, shales and anthracite beds. These 

 occur near the chalybeate spring, and are well seen in the course of 

 the brook below this spot. Immediately below the mineral spring 

 the shales cross the brook ; and here they consist of thin-bedded 

 layers of a dark grey colour. In following the brook downwards the 

 anthracite appears, and in it a horizontal shaft has been driven. This 

 deposit consists of thin beds, which are very much traversed by rents 

 in different directions, and intersected by numerous thin veins of 

 quartz. The dip both of the anthracite and of the dark shales is 

 indistinct, both being much contorted, the latter also being greatly 

 affected by movements which have produced slickenside surfaces. 

 The strike, however, is well-marked, and has an E.N.E. and W.S.W. 

 direction. Independent of the contortions in these beds, it is pro- 

 bable that they have a N.N.W. inclination at a high angle, that 

 being the prevailing dip of the greywacke in the hills which lie both 

 north and south of this locality. The relative position of the anthra- 

 cite and the shale to each other appears to be, that the former is an 

 inferior deposit upon which the dark-coloured shales repose. Amongst 

 the anthracite beds portions of Graptolites are sometimes met with ; 

 but these are not in general well-marked. In the overlying shales 

 similar fossils occur in great abundance and in a fine state of preser- 

 vation. They are referable to the genera Graptolites and Diplo- 

 grapsis, and the species found in this locality are mostly of this 

 latter genus. 



In following the direction of the strike of these beds of shale 

 and anthracite to the S.W., we come upon a narrow band of red 

 sandstone in the higher portion of the vale of the Annan ; after tra- 

 versing this, we again meet the greywacke of the Silurians ; and at 

 a small burn called Hawkshaw Linn, the dark shales and anthracite 

 beds also present themselves. At this locality, which is about four 

 miles along the strike from that previously mentioned, the same de- 

 scription of strata occurs ; the shales have, however, a redder aspect 

 and the inclination is more distinct. Continuing in the same direction 

 we find the shales and anthracite crossing the river Evan at a place 

 called Rittenside ; and a mile S.W. of Hawkshaw Linn, at Greskin, 

 in a cutting of the Caledonian railway, we come upon the same beds. 

 In some intercalated beds of compact greywacke which here occur, 

 orbicular bodies are found which seemed to resemble Crustacea of 

 the genus Cythere ; but they prove to be concretions only. The 

 inclination of the strata is here very distinct, being towards the 

 N.N.W. at a high angle ; a short distance below, in the course of 

 the river Evan, the dip is only 30° N.N.W. S.S.W. from this loca- 

 lity, at the west base of the RAvox Hill, the shales are again seen ; 

 and here their appearance was such as to induce a former tenant to 

 sink a shaft of considerable depth, under the impression that they 

 would yield coal. 



About six miles from this spot, in the same direction over the 

 hills, the shale and its concomitants are again exposed about half a 

 mile from the Shepherd's house at Branrigg, in a small brook which 



