THE GEOLOGICAL STRUCTURE OF THE CANONBIE COALFIELD. 



847 



Eurynotus, two species. 

 Mesolepis rhombus, Traq. 



„ tuberculatum, Traq. 

 Mesopoma politum, Traq. 



„ pulchellum, Traq. 



„ Ramsayi, Traq. 

 Phanerosteon mirabile, Traq. 

 Platysomvs supberbus, Traq. 

 Rhadinichtliys angustulus, Traq. 



EhadinicJithys dclicatulus, Traq. 



„ fusi/ormis, Traq. 



„ Macconochiei, Traq. 



„ tuberculatum, Traq. 



Sphenacantlms costellatus, Traq. 

 Strepsodus, two species. 

 Tarrasius problematieus, Traq. 

 Tristychius minor, Portl. 



The tuffs of the Glencartholm volcanic group have been traced for five miles towards 

 the E.N.E. to the head of Muir Burn that joins the Liddel Water at Liddel Bank, but the 

 richly fossiliferous shales have not been found in association with them. Chert beds, 

 however, accompany the tuffs and basaltic lavas in Muir Burn. The small outlier of 

 basic lava that caps the hill near Dinwoodie, east of Muir Burn, is probably on this 

 horizon. East of the Liddel we encounter this volcanic zone in the Kershope Burn, 

 about half a mile above its junction with that stream, whence its outcrop sweeps north- 

 wards by the top of Caerby Hill, and curves eastwards till it recrosses the Kershope 

 Burn and passes into Cumberland, about a mile and a half north-east of Kershopefoot 

 Station. Owing to the synclinal arrangement of the strata in Larriston Fells, the 

 basaltic lava on this horizon forms in that region a narrow outcrop, encircling sediments 

 at the base of the overlying Lewis Burn coal-bearing group. 



West of the Esk, this volcanic zone can be traced up the south bank of the Irvine 

 Burn, and still further to the west it appears in the Palling Burn — a tributary of the 

 Water of Sark — about four miles W.S.W. of Glencartholm. 



vi. Marine Limestone Series with Coal-seams. 



In Eskdale and Liddisdale the Glencartholm volcanic zone is followed in natural 

 sequence by sediments in which marine limestones are a prominent feature with thin 

 coal-seams on two horizons which have been worked at certain localities. The members 

 of this series may be classified as follows : — 



4. Upper Limestone group ..... 

 3. Kilnholm Coal group (horizon of Lickar coals) 

 2. Lower Limestone group ..... 

 1. Lawston Linn and Lewis Burn Coal group (horizon of 

 Scremerston coals) ..... 



Thickness. 

 300-400 feet 

 342 

 500-700 „ 



400-500 „ 



1. The Lawston and Lewis Burn Coal Group. — In Eskdale and Liddisdale the 

 members of this subdivision consist of sandstones, shales, thin coals, and thin marine 

 limestones. At Lawston Linn, on the Liddel, a coal from one foot six inches to two 

 feet thick was formerly extensively wrought on this horizon, which is the most 

 prominent seam. Other coals of less thickness, together with an oil shale, also occur at 

 that locality. Again, at Muir Burn, near the head of Archer Beck, similar thin coals 

 appear in this position. In the Esk section thin coals almost immediately succeed the 



