374 CRETACEOUS. 



main mass of the marine Lower Green sand above, and from the 

 freshwater Wealden below. Among the fossils noted by Prof. 

 Judd from the Punfield Beds are Exogyra siniiata, E. BoussingauUii, 

 Corbida stria tula, Cardiiim subhillanum, Anoniia IcEV/gata, Vicarya, 

 Cerithium, Ammonites Deshaycsii, etc. ; these occur in the Marine 

 band. The Punfield Beds attain a thickness of 65 feet at Wor- 

 barrow Bay, but they have not been noticed further west. Traces 

 of laminated clays and sands, probably on the same horizon, were 

 opened up in a cutting by Corfe railway-station. 



The sequence of beds below the Gault at Punfield is as follows : — 



Feet. Ins. 

 Grey clays alternating with ferruginous sandy beds. Exogyra 



sinuata, Panopcza Neocomiensis 60 O 



^Grey laminated shales with bands of limestone (Cypridiferous 



Beds), Cyi-ena media, Ostrca, etc., about 6 O 



Grey and ash-coloured sands, with interlaminated clays and 

 lignite, and seams and bands of ironstone. Bands near 



middle with 6'j-/';-m, etc. , 100 to 150 o 



Hard, laminated, micaceous sandstone \ 



Bed of oysters > Marine Bed. I 9 



Blue shelly limestone ) 



Blue clay with Area, and the marine Crustacean \ 



(Atherfield lobster) / , 



Clays with many Lower Greensand fossils i 



Line of ironstone nodules ) 



'Dark clays, with Cypris 7 ^ 



Grit-band, with Cypris and Fish-remains. 

 'rt I Blue Cypridiferous shales and clays. 

 > I Variegated clays and sands, etc. 





The beds marked above as Punfield Beds were so grouped by Prof. Judd, but 

 afterwards Mr. C. J. A. IMeyer obtained evidence of marine shells below the 

 'Marine Bed,' and he regards the entire series between the Wealden Beds and 

 Gault as a littoral facies of Lower Greensand.' The section was subsequently 

 studied by Members of the Geologists' Association, and some further important 

 particulars have been incorporated above, which tend to corroborate the views of 

 Mr. Meyer. 2 (See Fig. 54, p. 347.) 



The thickness of the Lower Greensand at Worbarrow Bay has 

 been estimated at 36 feet, excluding the Punfield Beds. At Mewps 

 Bay the Lower Greensand is faulted against the Wealden Beds, and 

 it is not seen at Lulworth Cove.^ Mr. Etheridge has stated that it 

 is represented by a bed of Carstone, i to 2 feet thick, at Black 

 Ven, Lyme Regis : * but westwards beyond this somewhat doubtful 

 representative, no Lower Greensand has been traced, although at 

 one time it was supposed that the Blackdown Greensand included 

 portions of it. Its abrupt termination near Lulworth is due in 

 part to faulting, but also to attenuation, and overlap by the Upper 

 Cretaceous strata. 



In Wiltshire the Lower Greensand consists of ferruginous beds 



' Q. J. xxviii. 250 ; xxix. 70. 



2 W. H. Hudleston, P. Geol. Assoc, vii. 388. 



^ Judd, Q.J. xxvii. 211 ; see also Godwin- Austen, Q.J. vi. 455 ; xii. 69. 



* Q. J. xxxviii. 93 ; xH. 26. 



