Reviews — The Work of the Geological Survey. 473 



The map (price Is. Qd.), which is very carefully printed in colours, 

 is published in two editions, on one of which (the Solid Edition) 

 glacial deposits and the like are omitted, while on the other (the 

 Superficial Edition) such deposits are indicated by colour, as well 

 as those portions of the solid geology which are not concealed by 

 Drift. The map of the solid geology, being nearly all covered by 

 the Coal-measures, the symbol of which is an olive-green colour, 

 has a sad and mournful effect, and renders it rather difficult to 

 decipher the names of places upon it. We think it might be possible 

 to use a somewhat paler colour with advantage. Manuscript six- 

 inch maps geologically coloured are deposited in the Survey Office, 

 Jermyn Street, where they can be consulted, and copies can be 

 obtained at cost price. 



2. " The Geology of the Cheadle Coalfield," by George Barrow, 

 forms a small but excellent memoir, complete in itself, of an outlying 

 portion of the North Staffordshire Coalfield, full particulars being 

 given of the various seams of coal, with records of borings and 

 remarks on the probable extent of the workable Coal-measures. 

 A good diagram-section across the coalfield is given on p. 49, 

 showing the various workable coal-seams. There are 17 seams of 

 coal, two being 6 feet in thickness, three over 3 feet thick, seven 

 of 2 feet and upwards, and the remainder only about one foot in 

 thickness. 



Details of the underlying Millstone Grit series and the overlying 

 Bunter and Keuper formations are also furnished, and special 

 reference is made to the water-bearing strata. The Glacial Drift 

 and other superficial deposits are described, and the memoir is 

 accompanied by a small but excellent colour-printed geological map, 

 a plan we hope to see followed in the issue of every separate Survey 

 memoir. 



The area described in this small memoir is remarkable for the 

 fact that its main features are of two widely different ages. What 

 may be broadly called the northern portion, is composed of Car- 

 boniferous rocks, forming a sloping tableland essentially of pre- 

 Triassic age, though modified of course by later denudation. Upon 

 this older land-surface the Triassic rocks were deposited, but have 

 since been denuded off all except a small portion of the northern 

 area ; thus restoring, as it were, the old pre-Triassic surface. In 

 the southern area, however, these rocks have escaped denudation 

 to a considerable extent, and now form a second and newer tableland, 

 overlooking the first and older one. The true form of the older 

 tableland is somewhat obscured locally by the hill of red sandstone 

 at Cheadle, but from the summit of the hill it is at once seen that 

 this isolated eminence is simply a detached portion of the newer 

 Triassic plateau, and really serves to emphasize the fact that these 

 rocks do form a tableland. 



The highest ground occurs in the northern area, formed of 

 Carboniferous rocks, attaining an elevation of 1,000 feet about 

 Ipstones, and 800 feet in the neighbourhood of Wetley Eocks. 

 The Triassic rocks do not attain so great an elevation ; at the edge 



