22 MIDDLE ALBIAN STRATIGRAPHY 



Subzone is represented in 9 (i), or whether 9 (iii) is of lyelli Subzone age, in the 

 absence of fossils cannot be determined at present. The Lower Gault can be divided 

 into six broad lithological divisions corresponding to those recognised by the 

 author in the Sevenoaks area (1958 ; 152 and text-figs. 3, and 9 herein), and the 

 correlation of these with Paddlesworth and the four divisions seen in the Maidstone 

 By-Pass is shown in text-fig. 3. Division 1 (i) has not yielded fossils, but 1 (ii) to the 

 top of 3 (i) are classified with the spathi Subzone. Division 1 (ii-iii) contain the same 

 species of Hoplites (H.) that occur in the dentatus nodule bed at Folkestone. Division 



2 is the ' upper dentatus-spathi nodule bed ' and contains the same ammonites that 

 were recorded by the writer from bed 4 in the Lower Gault of the Buckland Sand & 

 Silica Co. pit (Owen 1958 ; 151). 



No ammonites have been obtained from Division 3 (i), but at the base of 3 (ii) 

 crushed Anahopiites intermedins and A . praecox appear in the succession, marking the 

 base of the intermedins Subzone sediments, and range up through the remainder of 

 Division 3. The coarse development of A. praecox known to occur in Bed II (iii) at 

 Folkestone is found in the condensed bed 3 (iii), and Euhoplites pricei ranges through 



3 (iv) to the base of Division 4 (Milbourne 1963 table 1). The lower 4 feet 2 inches 

 (1-321 m.) of Division 4 contains crushed examples of Dimorphoplites niobe, and these 

 sediments are classified with the niobe Subzone. As Milbourne has demonstrated, 

 Mojsisovicsia subdelaruei and its contemporaries range throughout the remainder of 

 Division 4. The meandrinus Subzone is represented within the sequence from 

 Division 5 (i) to the top of 5 (v) . The clays of 5 (i) to 5 (iv) contain the same fauna as 

 Bed IV (iii) and the basal 2 inches (0-151 m.) of Bed V at Folkestone (Owen 1958 ; 

 157). However, 5 (v) was probably deposited at Trottiscliffe during a minor phase 

 of non-deposition at Folkestone. The marked change in the ventral aspect of 

 species of Euhoplites which occurs suddenly 2 inches (0-051 m.) above the base of 

 Bed V at Folkestone is not so abrupt at Trottiscliffe. In Division 5 (v) the peripheral 

 aspect is transitional from the sulcate to the channelled state. Nonetheless, the 

 characteristic species are more closely allied to the meandrinus Subzone rather than 

 the nitidus Subzone. 



Division 5 (vi) contains a typical nitidus Subzone fauna but at the top, immediately 

 beneath the cristatum nodule bed (Division 6), there are to be found the occasional 

 part-phosphatised examples of Anahopiites daviesi. Division 6 contains numerous 

 usually fragmentary fossils in a matrix containing crushed or partly phosphatised 

 fossils of cristatum Subzone age. There are well preserved phosphatised ammonites 

 with the shell which are of daviesi or nitidus Subzone age which have just been caught 

 up into the phosphatic debris of the nodule bed from the clays beneath. Nonetheless, 

 the clay sediment of Division 6 is of cristatum Subzone age. The phosphatic debris 

 contains ammonites indicating the daviesi Subzone, but essentially the cristatum 

 Subzone. 



At Trottiscliffe, therefore, as at Paddlesworth at least in part, we see an expansion 

 of the sequence found at the Maidstone By-Pass, but virtually all sediments of 

 daviesi Subzone age have been removed by the cristatum Subzone transgression. This 

 expansion of the sequence reaches its known maximum in this area at the Sevenoaks 

 Brick Works Ltd's pit at Otford. 



