Reviews — Mello's Geology of Derbyshire. 181 



A Sketch of the Geology of Derbyshire. By the Kev. J 

 Mageus Mello, M.A., F.Gr.S. 8vo. pp. 40. (London: Bemrose 

 & Sons.) 



THIS little Memoir, which was originally read before the members 

 of the Chesterfield and Derbyshire Institute of Engineers, is 

 published in a separate form, and as such will be found very useful, 

 not only to the geologist, but also to those tourists who visit the 

 picturesque Mountain Limestone dales which render Derbyshire so 

 attractive, and who may wish to inquire into their origin, and that of 

 the difi'erent rocks they meet with in their walks. The author treats 

 his subject in an easy and interesting manner, and at the same time 

 he has brought together as many of the principal facts relating to it 

 as could be condensed into so small a compass. 



He treats briefly of the peat-bogs so common in our moorland 

 districts, which cover a vast extent of the Millstone-grit and Yore- 

 dale formations of Derbyshire, and which those who wander up the 

 Kinderscout are likely to remember. The numerous springs which 

 issue from the Mountain Limestone, and the tufa they frequently 

 deposit ; the alluvial deposits of the Trent and Derwent ; and the 

 glacial deposits, which occur chiefly in the southern part of the 

 coimty, are also touched upon. 



The Keuper marls and sandstones occupy the larger part of South 

 Derbyshire ; gypsum occurs abundantly in the marls, and rock-salt 

 but sparingly, as indicated by slightly brackish water at Branstone, 

 though its former presence is proved in other places by numerous 

 pseudomorphous crystals. 



Beneath the Keuper beds come the Bunter sandstones and Con- 

 glomerates, upon the middle member of which the Keuper beds are 

 said to rest unconformably. 



The Permian beds are then treated of; they include the Magnesian 

 Limestone, which is so largely quarried for building purposes, espe- 

 cially at Mansfield, and the marls and sandstone which underlie it. 

 These lower beds contain fossils apparently identical with those of 

 the Coal-measures species of Lepidodendron, Sigillaria, and Ccdamites, 

 which would seem to connect them more closely to the Carboniferous 

 period, although not more conformable to its strata, than to the 

 marine beds of the Permian. 



Next we come to the account of the Coal-measures, Millstone- 

 grit, Yoredale Eocks, and Mountain Limestone. 



The latter rock furnishes some of the most beautiful scenery, and 

 is very interesting on account of the great intrusive beds of Trap or 

 Toadstone, which in places are at least 200 feet thick. The caverns 

 for which the Limestone district is so noted are briefly alluded to by 

 Mr. Mello ; and in speaking of the dales, he remarks that they "were, 

 probably, in many instances, originally caverns, which have been, 

 through countless ages, eaten away by the streams, till at length the 

 roofs have fallen in, and in their turn have been, for the most part, 



