Bath 

 Oolite 

 Series. 



1857.] PHILLIPS OOLITE AND LIAS, YORKSHIRE. 95 



Westow to its disappearance (through unconformity) below the chalk 

 at Kirby-under-dale. The rock emerges again from its cretaceous 

 covering at Sancton, near Market Wrighton, and is traced to Brough- 

 on-Humber, where it is quarried above grey partly micaceous sand 

 and sandstone, and is evidently equivalent to the Oolite of Lincoln- 

 shire, which appears on the opposite shore of the Humber, and rests 

 on sands, grey, red, brown or white, as these do on the Upper Lias. 



The only example which I propose now to present of the Lincoln- 

 shire sections is that of Harpswell Hill, north of Lincoln, which was 

 traced by myself in 1821, from the actual road-cutting*. The 

 series begins with — 



r White oolitic limestone 30feet. 



Pale clay and sand 12 



White sand ., 3 



Sandy with iron-balls 10 



S White micaceous sand 3 



Brown sand 4 



Clay parting 



Brown sandstones and shells 40 



Blue Lias clays, succeeded by marlstone and 



lower lias exposed 20 



Above the white oolite are clays and thin stony beds of the Forest 

 Marble series and Cornbrash. These have been fully illustrated in 

 South Lincolnshire by Prof. Morris f, and are found again with 

 similar characters at many localities in Oxfordshire. This white 

 oolite is perhaps generally admitted to be the Great Oolite of Bath, — 

 a point on which I reserve my opinion ; it is certainly represented 

 in Yorkshire by that of Cave, Westow, and Crambe. 



The Lias Formation. — The Lias varies not so much as the Oolites 

 in a given geographical area, because for the most part its materials 

 were accumulated from long and widely suspended fine argillaceous 

 sediment. The main differences observable in Yorkshire relate to 

 the upper part of this great series, and may be sufficiently illustrated 

 by three actual sections, representing the succession of beds seen in 

 the cliffs about Whitby, — measured in the works at Eston Nab, — 

 and explored in a boring at Feliskirk, near Thirsk. 



The Lias of the Yorkshire coast is exhibited in a complete and 

 magnificent section through all the upper and middle parts of the 

 lower groups for above 500 feet in thickness ; about 300 feet of beds 

 still lower being imperfectly traced in the interior. In general terms 

 the series^ stands thus (see Section No. 4, PI. VI.) : — 



f~ Alum-shale (80-)- feet), including cement-nodules and 

 ,, , . ironstone-nodules. In the upper parts, gradually 



v? , J diminishing downwards, are Discina reflexa, Nu- 

 900 f t i cu ^ a ovum > Ammonites bifrons, A. heterophyllus, 

 and Belemnites tubularis. Abundance of Enalio- 

 saurians. 

 * See Memoirs of W. Smith, p. 97. 

 t Quart. Journ. Geol. Soc. vol. ix. p. 317. 



X See Illustr. of Geol. of Yorkshire. Also a section of the Upper Lias and 

 Marlstone, communicated to the Geological Society, by Mr. L. Hutton, 25tb 

 Mav, 1836 ; Geol. Proc vol. ii. p. 41. This is an elaborate series of the Lias in 

 Rockcliff. 



