HARD WICKE'S SCIENCE- G OS SIP. 



169 



THE GEOLOGY OF YORK AND THE NEIGHBOURHOOD. 



I By C. FOX-STRANGWAYS, F.G.S., &c., H.M.'s Geological Survey. 



;HE British Associa- 

 tion has decided 

 to hold its annual 

 gathering this year 

 at York, where 

 fifty years ago its 

 first meeting was 

 held, and there is 

 little doubt that 

 the occasion will 

 be taken to trace 

 the progress made 

 in geological 



science during the 

 half century that 

 has passed ; but 

 this, howevei", we 

 may leave to abler 

 hands, our present 

 object being to 

 give a short sketch 

 of the geological structure of the district, such as may 

 assist the members of the Association in understand- 

 ing and appreciating the geological excursions which 

 always form so interesting and important a part of 

 these annual meetings. 



Since the Association visited York in 1831, much 

 has been learnt and written on the geology of the 

 county— in fact a complete list of all the publications 

 would occupy many pages of letterpress ; we cannot, 

 however, leave unnoticed a few of the most important 

 -and best known works relating to the subject ; of 

 these perhaps the most v.-idely known is Professor 

 Philip's " Illustrations of the Geology of Yorkshire," 

 the first part of which, that relating to the eastern part 

 of the county, originally appeared in 1829, and has 

 passed through three editions, the last of which was 

 issued in 1875. Of other works we may mention " The 

 Yorkshire Lias," by Messrs. Tate and Blake ; " The 

 Yorkshire Oolites," by W. H. Hudleston in the Proc. 

 Geol. Assoc; and also several papers by various 

 authors which have appeared in the "Proceedings of 

 No. 200. — August 1881. 



the Yorkshire Geological and Polytechnic Society," 

 and other publications. 



Unfortunately the publications of the Geological 

 Survey for the whole county of Yorkshire, and more 

 particularly for the immediate neighbourhood of York, 

 are not quite completed, although the majority of the 

 maps that now remain are in the hands of the 

 engraver. 



The city of York, as may be seen from any general 

 geological map, such as Philip's map of Yorkshire, 

 or Ramsay's map of England, stands about half-way 

 across the great central valley which traverses the 

 county from the Tees in the north to the Humber in 

 the south, and divides it into two more or less equal 

 halves ; the western portion, containing the Palaeozoic 

 rocks, including the Carboniferous Limestone, Yore- 

 dale beds. Millstone Grit, Coal Measures and the Per- 

 mian formation ; the eastern half the Mesozoic rocks, 

 including the Lias, the Oolites and the Cretaceous 

 rocks. 



The city of York itself stands on some portion of 

 the Trias, probably the Keuper sandstone, but as 

 there is a great thickness of glacial deposits in the 

 neighbourhood it is not easy to determine the exact 

 nature of the solid rocks below. The nearest place 

 that any member of the Trias is exposed is in a 

 cutting on the Harrogate railway near Cattal station ; 

 it is here a soft red sandstone similar to the usual 

 character of the Bunter sandstone. The Keuper 

 division of the Trias is not exposed until we nearly 

 reach the foot of the chalk wolds at a distance of 

 from nine to twelve miles from York ; it consists of 

 red marls, sometimes variegated, containing beds of 

 gypsum and thin sandstones. 



Although the city of York stands on the Trias, it has 

 been seen that there are no sections in the rock in its 

 own immediate neighbourhood; it therefore behoves 

 us to inquire what is there of geological interest to 

 be seen in the immediate vicinity of the town. The 

 superficial deposits, consisting of boulder clay and 

 gravel, and the alluvial or warp clay and sand attain 

 a considerable thickness, being met with in various 



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