246 Maw — Distribution of White Clays and Sands, 



All the examples of these white clays and sands in North Wales, 

 though varying much in the relative proportion of sands and clays, 

 bear an unmistakeable affinity in mineral character. To the west, 

 in the neighbourhood of Llandudno, sand strata predominate with 

 but slight traces of clays. In the neighbourhood of Holywell the 

 proportion of argillaceous strata is larger, though the sand beds are 

 still in the ascendancy, and in the most easterly examples about Mold 

 the sand strata are almost absent, and replaced with considerable 

 masses of white clays, with occasional layers of dark laminated 

 clays. 



BerbysMre and North Staffordshire. — For the followings facts I am 

 indebted to Mr. E. W. Binney, F.E.S., of Manchester, and Mr. E. Brown, 

 F.Gr.S., of Burton-on-Trent. Mr. Binney has placed at my disposal 

 his notes of several years' observations on the distribution of white 

 clays and sands, similar to those in North Wales — over the Mountain 

 Limestone district of Derbyshire and North Staffordshire ; and Mr. 

 Brown permits me to print a portion of his paper " On the Drifts of 

 the Weaver Hills," read before the British Association at Notting- 

 ham — the result of independent observations in the same district ; 

 and has obligingly supplied me with the section of the Weaver Hills 

 (Fig. 6)._ 



Mr. Binney observes : " In a good many of the mines and j&ssures 

 of the Mountain Limestone of Derbyshire, clay, sand, and gravel are 

 found ; at Bolsover and Lindric common, near Worksop, beds of 

 clay of a light colour occur on the top of the Magnesian Limestone, 

 but they contain no sand or gravel." 



The earliest notice of the white clays, in the Mountain Limestone 

 district of Derbyshire, appears to be in Farcy's '' General Yiew of the 

 Agriculture and Minerals in Derbyshire," published in 1811. In Vol. i., 

 page 249, he says : " Faults, as before observed, range along and have 

 broken the vein stuff and rake and pipe veins, and introduced rounded 

 Quartz pebbles, gravel and alluvial clay, and other extraneous mineral 

 matters below the Tick holes, which connect with the surface, and 

 such are often called soft veins or are said to be filled with ' softs.' " 

 These " Ticlc holes," connected with the surface, would appear to 

 be analogous with the "Pot holes" or Pockets of the Mountain 

 Limestone district of North Wales. Farey gives a list of mines in 

 which, what he terms " Alluvial clay and other extraneous matter " 

 derived from the surface have been met with ; but in many cases 

 it is difficult to distinguish whether the white clays and sands 

 resting on, and contained by pockets in the limestone, are referred 

 to. The following mines taken from his list appear to be the 

 localities of the white clays, sands or gravels underlying the Glacial 

 drift :— 



"Bald Mare," in Brassington, is given as the locality of China 

 clay and gravel. 



" Bonds Vein," North- West of Wirksworth ; in 3rd Lime — gravel. 



" Clay-pit Dale," near Hartington — China clay, and gravel. 



■' Dale Top," in Wirksworth — Gravel. 



" Green Linnet," West of Brassington — China clay. 



