Subjacent to the Boulder-clay. 



Ui. 



angle towards the north, and from the general lie of the ground and 

 the position of the Limestone rock to the south and north of the pit, 

 appeared to occupy a large pocket as represented in the accompanying 



diagram. 



Fig. 4. Clay Pocket, Pant du, near Ilanferris. 



A. Drift and Limestone DSbris. b. White Clay. c. Bireecia of DectrmpoEed Chert. 

 D. Dark Laminated Clay. e. Mountain Limestone. 



The bed d closely resembles the dark clay at Llangynhafal and 

 Fridd Garreg Wen, and appears to occupy the same position in rela- 

 tion to the pocket and its contents, as in the latter locality. 



At Maes y Safon Mine, about one mile and a half to the north 

 of Pant du, a similar bed of white clay was found in digging the 

 foundation for a windlass, but the depth and extent was not 

 ascertained. 



I am informed by Captain Cooke, of Cblomendy Hall, that about 

 a mile further to the north, near hia house,^ a shaft was sunk many 

 years ago, and said to- have penetrated white clay for more than forty 

 yards without reaching the limestone; but exact particulars are 

 wanting. The probable existence of the clay is rendered evident by 

 a sinking of the ground, below the general level, on all sides — a 

 phenomenon almost invariably accompanying these deposits. A 

 shallow pit sunk on the spot a few years since proved the existence 

 of the clay on the surface, though the full depth was not ascertained. 



Similar white clay has been found in sinking mine shafts in 

 several localities near Mold, in each case, as far as could be as- 

 certained, resting on the limestone under a considerable thickness 

 of Boulder-drift and limestone debris, and generally at a height of 

 from 800 to 1000 feet above the sea. At a pit a little to the west of 

 Trinity Church, three miles to the west of Mold, under 93 feet of 

 drift and loose limestone boulders, 45 feet of white clay similar to 

 that at Pant du, was penetrated ; and at Vron Hall Mine, at a depth 

 of 140 feet, a layer of white clay was found under the limestone debris. 



