Subjacent to the Boulder-clay, 



251 



almost vertically, and nearly level beds ending abruptly against those 

 steeply inclined. The superposition of the Boulder-clay was invariably 

 evident, and in one or two places I observed thin layers and seams of 

 the dark Till running in amongst the subjacent lighter deposit, as 

 though it, at the time of the deposition, had contained open cracks 

 on its upper surface, as in Fig. 7. 



In one case it was evident that the deposit had moved after the 

 deposition of the Till, the continuity of the thin dark Ihies being 

 abruptly broken by what appeared to be small slips in the white 

 sand and clay beds containing them. This is a point I shall have 

 further occasion to refer to in the latter part of the paper. 



Mr. Brown informs me that — " Somewhat to the east of the 

 Eibden Pit" (from which the example in Fig. 7 was taken) "is 

 another exposure of the white clay, superimposed by several feet of 

 Boulder-clay Till : the locality is known in the neighbourhood as the 

 Wredon or Sally-Moor Pit ; leading up from this past the Eibden 

 Pit, towards the Eed House, are several other interesting pits in this 

 deposit. At the south-west base of Caldon Low, and close to the road 

 leading to Caldon village, are two or three pits of rather impure 

 deposit. From the top of Caldon Low you may trace by the eye 

 the extension of the bed as marked by the sinkings mentioned in my 

 paper. North of Caldon Low are two or three other newly opened 

 excavations." 



[To he concluded in our next Nnniber.'] 



II. — On a Bed of Phosphate of Lime, N.W. of Llanftllin, 



North Wales. 



By D. C. Davies, Oswestry. 



AT the meeting of the British Association held in Birmingham 

 in 1865, Dr. Voelker directed attention to the discovery of a 

 bed of Phosphate of Lime in North Wales, and entered iato par- 

 ticulars concerning its chemical composition, and economical value. 



S. g B p4^N. 



g. 





"3 fc 



^ 





>a 









a 





Si^ 



Das Eithen. 



Ho 



1 2 3 A 



Fig. 1. Section showing the general structure of the country near the Phosphate 

 bed, north-west of Llanfyllin. 



1. R\ibbly shales, passing upward into soft sandstone, containing Ketepora, Favosites, Ortliis 



elegantula, O. par-va, Leptsona simulans, L. teniucincta (Llandovery beds). 



2. Schists, in centre of the hill, passing into impure limestone (Uppermost, or Hirnant band, of 



Bala limestone). 



3. Blue rubbly schists, passing into solid limestone, with bed of Phosphate, A. 



4 and 5. Levels driven into the hill, the lower cue (5) showing the return of the beds to theii- 

 natural position, x Quarries. 



