Geological Notes. By G. A. Lebour, M.A., F.G.S. 529 



compound and single in large quantities, crinoid stems often 

 forming whole " posts " of stone — these are tlie most obvious or- 

 ganisms, but tbey are not, as a rule, easy to obtain, being one 

 with, the stone and not separable without great skill and luck. In 

 the earthy and shaly bands between the limestone posts many 

 foraminifera are also found (7;, as at Colster Cleugh, within a 

 mile of the village where a handful of "stuff" yielded eight 

 species. 



Now these beds of limestone are so constant, or rather relative- 

 ly to the other beds of the series they are so constant, that it has 

 been the custom of geologists to rely chiefly upon them for theii' 

 horizons. But in this Elsdon locality there are a number of 

 faidts and disturbances of the strata, which disconnect it, so to 

 speak, from, the adjoining areas where the succession of the beds 

 is well known. It is owing to this, that the writer must confess 

 his inability, to correlate exactly these limestones with those of 

 the more southern, or of the more northern portions of the coun- 

 ty. All he can affirm is, that they are in the Lower Bernician 

 Series (bearing in mind that there is no hard and fast line be- 

 tween that and the Upper Bernician), and above the Harbottle 

 Grits — on or about the horizon of the Eothbury Grits. (8) After 

 all this is as near an approximation as most people can require. 



Although not forming very salient features the limestones are 

 apt to form picturesque waterfalls, wherever they cross rapid- 

 running burns, and these are not wanting here. At Todholes 

 Syke where the Burn runs down a steep slope of limestone, a 

 vein containing conspicuous strings of galena is visible. This is 

 within a few minutes walk of the village. 



But besides sandstones, shales, and limestones, coals occur also 

 in the district, and of no mean thickness for seams of Lower 

 Carboniferous age. They have been worked at Grasslees, be- 

 tween Elsdon and the Coquet, at several places in and near Bills- 

 moor Park, and close to Elsdon, between Otterburn and the 

 village. Near the turnpike a seam has frequently been worked 

 which has been proved to attain a thickness of nearly six feet, 



(7) See Brady's "Monograph of Carboniferous and Permian Foramin- 

 ifera," Palaeontographical Society's Publications for 1876, p. 29 



(8) In his " Outlines " the author inadvertently called these grits the 

 Simonside Grits (See p. 41). Mr W. Topley gave them the more appropri- 

 priate name of Eothbury Grits (See Guide to Eothbury and Upper Coquet- 

 dale, 1873). The term Simonside Grits has long been in use for some York- 

 shire deposits, 



