Geology. 213 



The Millstone Grit, or the miner's " Farewell 



Millstone Grit, -r, , ,, . , ^ , . , 



Rock, estimated as 1,000 ft. thick near 

 Bristol, is not so extensively developed in the Mendips, 

 or near Bath. According to Mr. McMurtrie, between 

 Coleford and Nettlebridge it does not exceed 500 ft. At 

 Wick, where it is faulted against the Carboniferous Lime- 

 stone, it is difficult to calculate its thickness. Lithologi- 

 cally, however, it corresponds with that at Bristol, and is 

 very close grained and quartzose ; frequently little rusty 

 grains are scattered throughout, and it is seldom so coarse 

 and conglomeratic in character as similar beds in the north. 

 Besides the before-mentioned localities, it may be seen at 

 Cromhall, Luckington, and Vobster. 



We now come to the Coal Measures proper,, 

 Measures. ^'^^ '^^ Consider that portion only of the 



Coalfield in our own immediate district — 

 i.e., the southern basins of Somerset and Radstock, which 

 are separated from that of Bristol and Gloucester by the 

 Kingswood anticlinal. Only a small portion of these Mea- 

 sures are exposed at the surface, owing to the covering 

 of the Secondary rocks which lie unconformably upon their 

 upturned edges. Our remarks shall be based on Mr. 

 McMurtrie's communications to the Proceedings of the Bath 

 Natural History and Antiquarian Field Club, vols. i. and ii. 

 Taking the Radstock district first, as the most important,, 

 about seven miles distant in a bee line from the city, we 

 there find the strata tossed about and disturbed in every 

 possible way, and consisting of two main divisions, an upper 

 and lower, separated by a great thickness of Coal Measure 

 Sandstone, locally called Pennant — the upper, about 2,200 ft., 

 thick divided into the first, or Radstock, series; and the 

 second, or Farrington. The upper includes all the coal bear- 



