42 MIDDLE ALBIAN STRATIGRAPHY 



This section has been discussed by Osborne White (1924 ; 29) Kirkaldy (1935 ; 526) 

 and Casey (1961a ; 559-560). The eodentatus Subzone is present within Bed 4, and 

 the lyelli Subzone within beds 4 and ?5. 



Further east in Sussex there is very little information about the Lower Gault other 

 than that recorded by Clement Reid (1898), Jukes-Browne (1900) and Osborne 

 White (1924 & 1926). Spath demonstrated that at Ringmer the daviesi Subzone is 

 represented (1926a ; 154) and it seems from the well records (Edmunds 1928) that the 

 Middle Albian sediments probably maintain the thickness seen at Small Dole and may 

 well thicken a little. The major increase in thickness of the Gault eastward is mainly 

 explained by the change in facies from Upper Greensand to Gault. This is certainty 

 the case in the Lewes area where the proven Upper Gault is very thick. 



The discovery of a nodule bed of spathi Subzone age in the sea-bed ESE. of Beachy 

 Head was used by the writer as evidence of an attenuation of deposits of this age in 

 that area (Owen 1963a ; 46, 48, text-fig. 2). However, phosphatised Hoplites (H.) 

 occur in Division 4 at the Horton Clay Pit where the sequence is very thick, and the 

 record of the Eastbourne Waterworks well given by Jukes-Browne (1900, 118) is 

 probably misleading. 



B. Isle of Wight, and Dorset Coast 



This section deals with the outcrops in the Isle of Wight, from Punfield to Osming- 

 ton, and from near Seatown to the Devon border (text-fig. 18). Of necessity the 

 account is very incomplete for the exposures are seldom good and the facies is such 

 that ammonites are uncommon except at a few horizons in the various localities. 

 For this reason no correlation diagram is given on this occasion. Despite the 

 difficulties, useful results have been obtained. 



(i) ISLE OF WIGHT 



The Carstone, and the overlying Gault (aptly named the ' Blue Slipper ') describe, 

 except in the centre of the Island, narrow outcrops from Redcliff near Culver in the 

 east to Compton Bay in the west. This is in response to the high dip on the northern 

 limb of the Sandown and Brighstone anticlines respectively. Where the two axes 

 meet in the centre of the Island there occurs a structural ' no-man's land ' with com- 

 paratively gentle northerly dips and thus a broader outcrop. An outlier of Chalk 

 and Upper Greensand in the southern part of the island is fringed by outcrops of 

 Carstone, and Gault dipping gently south. The Carstone and Gault have been 

 described in stratigraphical detail notably by Bristow et al. (1889), Jukes-Browne 

 (1900 ; 126-130), Osborne- White (1921), Kitchin & Pringle (1922a ; 160-161), Spath 

 (1943 ; 741-743), and Casey (1961a ; 512-515), but there are many other references to 

 them in the literature. The Gault is responsible for the major landslips on the 

 southern coastline, and much of the outcrop is obscured by slipping, sludging, and 

 deep weathering. The sections that are available are not always easy to work and 

 fossils are far from plentiful. 



Fig. 18. Sketch map showing positions of sections in South West England discussed in the text. 



