104 Mr. Farey's Geological Observations 



conducted to the north of the Road, and of Fairbnrn o]<I 

 Limestone Quarries, and in the midst of a common-field, 

 the general Turfacc of which is Limestone with many shal- 

 low quarries in it made by the Farmers ; we ascended a de- 

 tached hummock of perhaps four or five acres exlent and 

 40 or 50 feet high, in the SE side of which the Gypsum 

 is dutr, ill '1 gy^'^l number of thin regular beds in red marl, 

 nowise materially different from all the Gypsum quarries 

 that I had previously seen in this m»i:l, except perhaps that 

 the beds of Gypsum are move numerous and thinner than 

 usual : standing on the top of this interesting hummock 

 (which has been dug over for Gypsuu)) with Mr. S. I re- 

 marked to him, that here were certainly undisturbed strat<\ 

 upon the Limestone Rock that we hul ascended from the 

 Coal-measures, and that the green hills in the inclosures to 

 the north, showed marks of the ancient diggings of Gyp- 

 sum or Marl in their sides, and doubtless were similarly 

 constructed to that on which we stood : but observing, that 

 the Limestone hill about five or six furlongs to the east of 

 us, on which the village of Fairburn stands and the great 

 North Road passes north of it, was much higher than the 

 Limestone field that surrounded us, or than this hummock, 

 I remarked, that cither a fault must range between us and 

 that hill, and had raised that so n)aterially (previous to the 

 denudation that had left these singular hummocks), or, that 

 there were two Limestone Rocks, on the upper of which 

 Fairburn stood, and Newton on the lower, and that these 

 Marl hummocks were the remains of a stratum between 

 these Rocks. We lost no time in reaching Fairburn to 

 verify, if possible, one or other of these suppositions, and 

 soon found on inquiry, that several of the Weils in the village 

 had been sunk through Limestone into sinular Marl with 

 Gypsum beds: a more decisive proof however immediately 

 offered itself, in a Tunnel that Mr. George Althas had about 

 two years beforedriven under theVillage and Turnpike Road, 

 at 34 feet deep, for conducting a rail-way branch from the 

 Air Navigation, into the deep Limestone quarries N of the 

 Road, which Tunnel passed along this Marl and Gypsum 

 stratum : in examining of which in its place at bottom of 

 the quarry, 1 was then and since able to detect several errors 

 that I had fallen into when on my Derbyshire Survey, and 

 examined patches of loamy Sand and inarly substances on 

 the planes of Yellow Lime, in different places, and which, 

 from having seen or heard no instance of such basseting, or 

 having a regular place between the Limestone Rocks, and 

 owin" chiedy to the vicinity or admixture of the Sherwood- 

 * ' Forest 



