YORKSHIRE TYPE AMMONITES— 11 



May 

 1913 



Geological Details (Lower Oolites) 



The upward continuation of the stratigraphical Table given in 

 Vol I p xvi may now be presented. The important bed in the Lower 

 Oolites, in connection with Ammonites, is the Scarborough Limestone, 

 which 'was deposited, perhaps more or less discontmuously, during 

 tain hemera about the middle of the Bajocian Age. A considerable 

 portion of the rest of the Yorkshire Lower Oolites consists of estuarme 

 strata, which can only be dated approximately : it is possible that there 

 are some considerable non-sequences— that, for instance, there may be 

 really no deposit at all representing the Bathian Stage. 



For further details and for information as to the dating, see 

 L. Richardson, " Lower Oolitic Rocks of Yorkshire " ; Proc. Yorksh. 

 Geol. Soc. XVII (3), 1911, 184-215. 



TABLE I— STRATIGRAPHY 

 See Vol. 1, p. xvi 



Stages, Zones (Hemerae) and Yorkshire Lower Oolites 



Stage Zone (or Hemera) Stratal Terms ( Yorkshire) 



discus 

 marmorea 1 

 digona 2 

 digonoides 3 

 bathonica 1 

 waterhousei 

 morrisi 

 gracilis 

 / acuminata 4 

 fusca 

 zigzag 



schloenbachi 

 truellii 

 1 garantiana 

 niortensis 

 Teloceras . . 

 Stepheoceras 

 Stephanoceras 

 Stemmatoceras 

 "N sauzei 

 Witchellia 

 Shirbuirnia 

 post-discites 

 \discites 

 concava . . 

 bradfordensis 

 murchisonae 

 Ancolioceras 

 scissum 

 opaliniforme 

 l aalensis 



Absent ? 



Absent ? 



or represented more or 



less by part of 



Upper Estuarine Series. 



Upper Estuarine Series. 



More or less represented 

 by the Moor Grit. 



Scarborough 

 Limestone, or 

 Grey Limestone, 

 (Bath Oolite— Phillips). 

 Middle Estuarine Series, 

 or Middle Shale and 

 Sandstone. 

 Millepore Limestone, 

 Whitwell and Cave Ool. 

 Lower Estuarine Series, 

 with Ellerbeck Bed. 

 The Dogger. 

 ? The Nerinaea Band. 



Absent ? 



Stratal Terms (General) 

 Cornbrash (pars). 

 Forest Marble. 



\ Upper 

 Great I Fullers' Earth, 

 Oolite. J wholly, or 

 / in part. 

 F. E. Rock. 

 Stonesfield Slate. ) Lower 

 Fullers' Earth. [F. E. 

 Fullers' Earth / Inferior Oolite 

 (locally). / (locally). 



Upper Inferior Oolite. 



/Middle Inferior Oolite. 



ILower Inferior Oolite. 



lEpithyris. *Ornithella. 



'Ornithella digonoides, nov. A species much stouter and less angulate 

 than O. digona, J. Sowerby sp., Min. Cinch, xcvi, I, 2: more approaching his figs. 4, 5. 

 It is from Great Oolite of Northamptonshire. 



*Ostrea. 



