GEOLOGY 



Corrected and Revised by J. Edmund Clark, B.A., B. Sc, assisted 

 by H. M. Platnauer, B.Sc, A.R.S.M. 



[For fuller information on this subject, see Phillips' ' Illustrations of the Geologj' of 

 Yorkshire ' (an elaborate work in two quarto volumes, with numerous coloured sec- 

 tions and figures of fossils), and the same author's ' Rivers, Mountains, and Sea- 

 coast of Yorkshire.' Sedgwick's Monograph on the Magnesian Limestone, in the 

 Transactions of the Geological Society, new series, vol. 3, p. 37-iiS ; and Williamson 

 on the fossils of the Yorkshire coast, Geol. Trans., n. s. vol. 5. Besides these works, 

 available at the time of the first edition, the following may be mentioned among many 

 which deal more or less directly with the district in question : — Phillips' Geology of 

 the Yorkshire Coast, 1875, edited by R. Etheridge ; The Yorkshire Lias, by R. Tate 

 and J. F. Blake (Van Voorst) ; Papers on the Yorkshire Oolites, by W. H. Hudle- 

 ston (Proc. Geol. Assn., Aug. 1874, Jan. 1S75, and Oct. 1878); Ordnance Survey 

 Maps and Memoirs, especially upon ' The geology of the country between Whitby 

 and Scarborough,' by C. Fox Strangways and G. Barrow. For general relationships 

 to other parts, Woodward's ' Geology of England and Wales ' is very valuable, and 

 Harrison's chapter on the North Riding, in his ' Geology of the Counties of England 

 and Wales,' is a useful summary. Lebour's ' Geology of Northumberland and 

 Durham' also treats of the Cleveland district.] 



With the exception of a small tract of Basalt in Upper 

 Teesdale, and a narrow dike or terrace of the same nature which 

 enters Yorkshire east of Middleton in the same valley of Tees 

 to penetrate the Cleveland moors, all the subjacent rocks of North 

 Yorkshire are of the kind which owe their origin to the gradual 

 deposit of sediment from water. Except in the shape of loose 

 fragments in the glacial drift, we have not either Slate, Granite, 

 or Chalk : and although Kainozoic deposits are met with just 

 beyond our boundary, except the glacial drift all the sedimen- 

 tary deposits which- occur within the limits of our field of study 

 belong either to the Palseozoic or Mesozoic periods. In order 

 of deposition they range either from west to east or from north- 

 west to south-east, so that a person travelling in a direct line 

 from the Derwent valley, opposite Filey, to the summit of 

 Cronkley fell in Teesdale, would pass over each of the series of 

 strata in succession, and each change would be from rocks of 

 a more recent to those of an earlier date of deposition ; or if he 

 were travelling in an opposite direction each change would be 

 from rocks of an earlier to those of a later date. The following 

 table will shew their order and geological classification : — 



Jan. 188S. 



