THE SOUTH-EASTERN COALFIELD 391 



The Atherfield Clay (983 to 1,000 ft.). 



From 983 to 987 ft. we find a sandy facies of this clay r 

 containing nodules slightly phosphatic ; it is also somewhat 

 micaceous ; from 988 to 993 ft. it is a fine micaceous silt. At 

 993 ft. we get the true brown Atherfield Clay, down to 1 ,000 ft. 

 In the arenaceous character of its upper part it resembles the 

 clay in the Isle of Wight rather than at Dover. It is a remark- 

 ably persistent bed, and we find it thickening somewhat from 

 Fredville eastwards and northwards. It is this thickening of 

 the Atherfield Clay at the expense of the Sandgate and Folke- 

 stone Beds that is the most striking feature of the subterranean 

 extension of the Lower Greensand in East Kent. From the 

 point of view of the mining engineer this is of course highly 

 satisfactory. 



The total disappearance of the Hythe Beds is a very re- 

 markable feature, as they are so strongly developed at their 

 outcrop not many miles distant. 



The Weald Clay (1,000 to 1,006 ft. 6 in.). 



The Weald Clay is sharply distinguished from the Atherfield 

 Clay in a core raised from 1,000 ft., in which the upper portion 

 is light brown in colour and solid, while the lower portion is 

 blue-grey, splits easily along the bedding-planes, and is covered 

 with Cypridea valdensis. Some of the bedding-planes are 

 literally crowded with Cypridea, and contain numerous vertebrae 

 and scales of Lepidotus and other fishes. At 1,005 ft- there is a 

 band of strong, hard clay-stone. The thickness of the Weald 

 Clay in this section is only 6 ft. 6 in. 



The Hastings Beds (1,006 ft. 6 in. to 1,035 ft-)- 



These beds begin at 1,006 ft. 6 in., and are 28 ft. 6 in. thick — 

 a remarkable and satisfactory attenuation, for they are apt to 

 be troublesome sinking ground. The upper portion is a pale 

 greenish-grey silty clay, with a few traces of plant remains : 

 below 1,009 ft- ft becomes more argillaceous, resembling the 

 " indiarubber clays or muds " met with at 490 ft. in the Dover 

 pits; at 1,012 ft. it becomes more silty, and we find the india- 

 rubber clays interlaminated with the silt; at 1,019 ft. there is a 

 nodule containing Cypridea, casts of shells, and fish remains ; at 

 1,025 ft. there is a vertical slicken-sided plane, evidently due to 

 interstitial movement within the mass ; at 1,026 ft. it is exceedingly 

 pale buff, almost creamy, in colour; from 1,028 ft. it becomes 

 more argillaceous and Cypridea and fish remains more abundant ; 



