206 C. Lapworth — Geology of Galashiels. 



mining the age of the strata, the whole fauna seems to point to a 

 very low place in the system, and Professor Harkness appears quite 

 justified in referring the whole group to a position inferior to that of 

 the Moffat Series. 



Now, it is of this especial portion of the Scottish Lower Silurians I 

 have to speak, and I trust I shall be able to show, from its fossil 

 contents, that it is not only superior to the Moffat beds, but that the 

 evidence goes far to show that it is the representative, in time, of 

 part of the Coniston group of England, or in other words, of a portion 

 of the Caradoc formation of the typical Siluria. 



THE LOWER SILURIANS OP GALASHIELS. 



The town of Galashiels lies about four miles to the south-east of 

 the Thornilee Quarry, mentioned above, and, as nearly as I can ascer- 

 tain, about the centre of the puzzling group of strata I have more 

 particularly noticed. Until within the last year no fossils had been 

 found in the neighbourhood, south of Thornilee ; and it is with their 

 discovery, and the light they throw on the position and age of the 

 strata, I have more especially to deal. 



My colleague — Mr. James Wilson, of Galashiels — and myself, 

 assisted by Mr. Wardrop, of Ladhope, have devoted much of our 

 leisure to the careful examination of the rocks of the neighbourhood, 

 during the past summer, and have found them to be abundantly fossil- 

 iferous in places, and to contain what seems to be a distinct and 

 characteristic fauna. 



The rocks from which fossils have been obtained stretch in a 

 north-westerly direction from the Eildon Hills, through the town of 

 Galashiels, to the Thornilee Quarry ; and as the Grieston contains 

 the same fauna, generally speaking, as that of our higher beds, I 

 shall include that classic quarry in my description. 



The whole series, which may be called "The Gala Group," is 

 separable into four main divisions, in what seems to be the ascending 

 order, viz. : — 



1. The Abbotsford flags and Greywackes, 



2. The Gala Grits, 



3. The Buckholm Sandstones, 



4. The Slates of Thornilee and the Grieston, 



the whole underlain by the representative of the higher portion of 

 the Moifat Series, or Anthracitic Schists. 



All these beds dip, as a rule, to the N.W. till they reach Thornilee, 

 where they turn over to the S.E., and continue thus to Innerleithen, 

 where the N.W. dip is resumed and is held to the Grieston. 



The average dip is about 60°, and the total distance across the 

 strike about three miles, which gives us a gross thickness, in round 

 numbers, of 13,000 feet. Allowing one-third of this for folds, we 

 have a net thickness of about 9,000 feet, to which, if we add 1,000 

 feet for the slates of Thornilee and the Grieston, we get an approxi- 

 mate thickness of 10,000 feet for the whole of the known Gala Group 

 — or less than one-half that estimated by Professor Harkness (Geol. 

 Journal, vol. xi., p. -393). This is the greatest thickness possible; 



