22 MESOZOIC AND CAINOZOIC DINOFLAGELLATE CYSTS 



Studland Bay. One of the most westerly outcrops of the London Clay is found 

 at Studland Bay in Dorset, where conditions in the Lower Eocene fluctuated between 

 marine and fresh-water, being very close to, and at times marking, the shoreline of 

 the London Clay sea. As with all cliff sections of the London Clay, difficulty is 

 experienced in collecting because of slumping. This obscures most of the London 

 Clay but fortunately both lower and upper junctions with the Reading and Bagshot 

 Beds are exposed. 



Because of the poor exposures, samples could only be taken haphazardly, three 

 (ST. 1-3) being collected within 10 feet of the base, and one (ST. 4) from only three 

 feet below the junction with the Bagshot Beds. The London Clay at Studland is, 

 at the base, an arenaceous yellow brown clay passing upwards into a friable yellow 

 argillaceous sand ; the succeeding Bagshot Beds are almost pure quartz sands, 

 bright yellow in colour and partly consolidated. 



Isle of Wight. The exposures of London Clay in the Isle of Wight at Alum 

 Bay and Whitecliff Bay are of importance because they give the only continuous 

 exposures through the whole London Clay, from the junction with the Reading Beds 

 to the base of the Bagshot Sands. The dip of the beds is almost vertical and they 

 strike at right angles to the exposure, thus providing comparatively easy conditions 

 for collecting. The main difficulty is slumping or slipping, which is a common 

 occurrence in the Alum Bay section, less frequent at Whitecliff. Only the White- 

 cliff section has been studied because it is less affected by slumping and the junction 

 of the London Clay and Bagshot Beds can be more precisely placed. 



Sheppey 



h 



Studland 



Whitecliff 



Fig. 6. Map of South-east England, showing in black the outcrop of the London Clay. 

 The localities from which samples were collected are shown by the arrows. 



