TI1K KOCENE SKKIKS 





It will be noticed that C and D form a zone of Nummulites 

 Icevigatuti, while A and 1! are characterised by Num. variolarius. 



On reaching Alum Bay we find that the greater part of this 

 group is represented by unfo&siliferous eands and clays, probably 

 estuarine beds, and that marine shells are only found in the upper- 

 most 157 ft-ct, which answer to Mr. Fisher's group A. The lower 

 beds were formerly relegated to the Lower Bagshot, but their true 

 position has lut n determined by Mr. Gardner, who has compared 

 them bed by bed with those of the opposite cliffs of Hampshire. 7 

 Their thickness is 398 feet, making a total of 555 fi-.-t. 



The succession of the Bournemouth and Boscombe Beds has been 

 carefully worked out by Mr. Gardner, who gives it as follows : 



6. Dark sandy clays with pebbles at base .... 



.'. II ighcliff Sands, white and without fossils 



4. Hengistbury Clays, with septaria containing sharks' teeth 



3. Boscombe Sands, of various colours containing pebbles 



2. Bournemouth marine beds, with plants and marine shells 



1. Bournemouth freshwater beds, with plant remains only . 



Feet. 

 14 

 31 

 57 

 140 

 50 



.'400 



About 590 



The Freshwater Beds consist largely of sand with occasional 

 bands of clay in which leaves are abundant, especially those of 

 Salix (willow), Triartea (a palm), Sequoia Coutssce, Araucaria, 

 Eucalyptus, and the ferns Osmunda, Polypodium and Acrostichum. 



The marine beds are a similar set of deposits, but among the 

 plants are Palmacites (a cactus), Dryandra, and the fruits of the 

 Nipa palm. 



Barton Beds. The most careful study of these beds is the 

 memoir by Messrs. Gardner, Keeping, and Monckton, 8 on which 

 the following account is based. They divide the stage into three 

 parts, which they call Lower, Middle, and Upper Barton, but the 

 Geological Survey divide it into the Barton Clay and the Barton 

 Sands, which is in some ways a more convenient division. 



According to these authors the thicknesses of their divisions at 

 the three principal sections are as follows : 



Barton Sands or Upper Barton 



The Lower Barton has at its base a thin zone of green sandy 



