606 ME. C. B. WEDD ON THE [NoV. 1 898, 



Corallian area by denudation, I have found evidence of denudation 

 of the surface-oolite in the material from the Lower Greensand 

 phosphate-beds which overlie part of the western flank of the 

 ridge. In this, rounded pebbles formed of Corallian pisolites 

 often contain phosphatic nodules, small quartz-pebbles, and Green- 

 sand brachiopoda, showing denudation and reconstruction of the 

 oolite in Lower Greensand time. Consequently the oolite now at 

 the surface was not originally the highest ; but in the Southern 

 Quarry the original top of the oolite is preserved beneath the Rag. 



In the autumn of 1897 a small section was opened near the 

 southern end of the ridge and on the western side of it, more than 

 5 mile from the Southern Quarry, in a corner of the fi.eld immedi- 

 ately north of the Inn-yard, and close to the road (see sketch-map, 

 p. 612). The section is cut obliquely through a little spur which 

 runs out south-westwards from near the end of the ridge. I sub- 

 sequently excavated a little farther in the bottom of this cutting ; 

 the following deposits were exposed : — 



Feet. In. 



5. Soil, with lumps and grains of limestone 1 to 1 6 



4. Hard, whitish, much-broken, rubbly limestone; many spines of 



Cidaris florigemma, ossicles of Pentacrinus, and other fossils . 1 to 1 6 



0. A bed almost entirely composed of ossicles of FentacHnus in a 



yellowish calcareous matrix 2 to 1 



Passing down into — 

 ^(e) Soft, yellowish-grey, calcareous marl with ossicles of Fen- 

 tacHnus; limonite-stains along the bedding-planes and on 

 the surface of minute joints, of reticulate appearance in 16 



j the lower part. Passing down into — 



I (h) Soft laminated grey marl with occasional small ironstone- 

 2. \ nodules, thin layers, blotches, and reticulations of limo- 



nite ; the marl alternating with hard flaggy layers of 

 crystalline limestone full of Thecosmilia, one of these 

 layers being at the bottom ; ferruginous oolitic grains in 



the lower part 1 



(a) Soft, dark grey, clayey marl with ferruginous oolitic grains. 3 



1. Light, yellowish-grey, impure limestone full of ferruginous oolitic 



grains (Els worth Rock) 9 



7 6 



There are at intervals from top to bottom thin, hard, crystalline 

 bands with traces of coral-structure (Isastrcea or Thamnastrcea), as 

 in the Rag. Near the bottom these bands are more or less con- 

 tinuous, but higher up they are shattered and displaced, yet still 

 for the most part recognizable as bands. I could find no trace of 

 unconformity in the section, and I was much struck by the resem- 

 blance of the lowest bed to the Elsworth and St. Ives Rock ; but, 

 owing to want of sufiicient fossil-evidence and the improbability of 

 finding ' Lower Calcareous Grit ' so high (and the evidence of fossils 

 from the overlying white limestone was strongly in favour of a high 

 horizon), I was inclined to regard the resemblance as a mere co- 

 incidence, and waited for further light on the matter from a well 

 which, as it appeared, was to be sunk close by. Being fortunately 

 present immediately after the opening of the above section, and while 



