Geological Society. 189 



numerical proportion, and, to some extent also, the morphological 

 character of the macroscopic fossils of the Phosphatic Chalk are 

 exceptional. The majority of the French deposits of Senonian age 

 appear to belong to a distinctly-higher horizon. The authors give 

 evidence to show that a part, at least, of the phosphatized material 

 has acquired its distinctive mineralogical character on the spot. So 

 far as can he ascertained from existing data, the Phosphatic Chalk 

 is confined to a small tract of country measuring less than 3| miles 

 from north-east to south-west by less than 1 mile from north-west to 

 south-east. It occurs as an intercalation between the normal Chalk 

 and the Lower Eocene (Reading) Beds, and occupies a structural 

 trough which coincides with, and is probably due to, a synclinal 

 flexure. 



April 19th.— Horace B. Woodward, Esq., F.R.S., 



Vice-President, in the Chair. 



The following communications were read : — 



1. ' The Blea-Wyke Beds and the Dogger in North-East York- 

 shire.' By Robert Heron Rastall, B.A., F.G.S. 



The author describes the type-section at Blea Wyke in detail, 

 dividing the rocks into the following divisions, enumerated in 

 descending order : — 



Feet Inches. 



5. Dogger 11 6 



4. Yellow Beds 53 



3. Scrpula-Beds 10 6 



2. Linfjula-Beds 32 



1. StriatulusShaleB. 



Descriptions and fossil-lists from these divisions are given, and 

 then the succession is compared with that shown at Peak Alum- 

 Works, Saltwick & Whitby, Sandsend & Kettleness, Boulby Cliff, 

 Falling Foss & Littlebeck. Eskdalesidc & Grosmont, Glaisdale, and. 

 along the north-western escarpment of the Cleveland Hills. A 

 complete series from the Lias to the Lower Estuarine Series is seen 

 only at Blea Wyke ; at other sections the transition from Alum- 

 Shale to Dogger is abrupt, and the characteristic passage-beds are 

 absent. In all these sections there are signs of unconformity, and 

 in most cases there is a well-marked pebble-bed of peculiar 

 character. In many localities the upper surface of the Lias is worn 

 into distinct hollows, in which lenticular masses of sandstone have 

 been deposited. Probably shallow-water conditions and strong- 

 currents prevailed over a wide area. This was most likely brought 

 about by a slow elevation which was more prominent in the northern 

 part of the area, as though the Peak Fault were partly of pre- Oolitic 

 date. This fault probably formed a submarine cliff, and in the still 

 waters at its foot the Blea-Wyke passage-beds were formed. North 

 of the fault erosion was active, planing down the Lias to a more or 

 less level surface, with occasional deep hollows due to strong 



