870 DR B. K PEACH AND DR J. HORNE ON 



strata from the top of the Dryburn limestone to the base of the Millstone Grit (600 feet). 

 At the base of the Upper Calcareous subgroup lie the Lickar coals (see PI. IV.). 



On the shore from Spittal, south-east to Cheswick, at low water, there are tolerably 

 continuous sections of the Lower Calcareous subgroup, where the individual bands 

 may be studied to advantage. The characteristic feature of the group is the presence 

 of marine limestones, charged with corals, brachiopods, gasteropods, and other organic 

 remains, indicating true marine conditions. In the lower portion there are three 

 marked beds of limestone, the Dun, the Woodend, and the Oxford (see PI. IV.), with 

 sandstones, shales, thin seams of coal, and a band of oil- shale. In the upper part of 

 this subgroup the marine limestones appear in force, which are here given in descend- 

 ing order, with the local names given to them at Lowick. # 



No. 1 Limestone (Dryburn) . . . .25 feet. 



,, 2 ,, (Low Dean) .... 



„ 3 „ (Acre) . . . . 20 „ 



„ 4 „ (Eelwell) . . . . 20 „ 



Sandstones, shales, and thin coal-seams are associated with these limestones ; the 

 highest (No. 1) being eventually succeeded at Cheswick by the Lickar Main coal, 

 which was formerly wrought at that locality. 



Our late colleague Mr Gunn states in his valuable paper on " The Correlation of 

 the Lower Carboniferous Rocks of England and Scotland," that these four limestones 

 (Nos. 1 to 4) have been traced almost continuously for nearly 100 miles in the northern 

 counties of England, under various local names, so that there can be no doubt as to the 

 identity of the limestones.t 



At Lickar, about one mile north of Lovvick, a small group of coals (the Lickar 

 coals) succeeds the Dryburn limestone, embracing three and in some sections four seams, 

 which seem to be inconstant.! These, in descending order, are the Limestone coal, 

 Parrot coal, Rough coal, and Main coal. 



South of Alnwick, towards Shilbottle and Felton, on the river Coquet, the repre- 

 sentative of the Dryburn limestone is followed by the Upper Calcareous subgroup, 

 including several limestones, the highest of which, laid down on the Geological Survey 

 map (sheet 109, S.W., old series), is the Fell Top band. This subdivision is followed 

 towards the east by the Millstone Grit and the Coal-measures. 



The evidence now adduced shows clearly the striking resemblance between the 

 sequence of the Lower Carboniferous rocks in Northumberland and that in Eskdale and 

 Liddisdale, which is represented in graphic form in the vertical sections in PI. IV. 

 Apart from the resemblance in the successive groups, the correlation is further 

 strengthened by the fact that some of the subdivisions have been traced more or less 

 continuously from the one region to the other. For example, if we exclude the area in 



* Mem. Geol. Sur., — Geology of Coast south of Berwick-on-Tweed, p. 16. 



t Trans. Edin. Geol. Soc, vol. vii. p. 365. 



J Mem. Geol. Sur., — Geology of Belford, Holy Island, and the Fame Islands, p. 39. 



