A HISTORY OF LEICESTERSHIRE filled with a curious white sandstone or indurated marl. The limestone is very fossiliferous, especially at Ticknall. 1 Corals are fairly plentiful, as also are the stems of Crinoids, and several species of Brachiopoda. At Breedon Cloud the limestone is burnt for lime, certain bands being said to make the best agricultural lime, while the more irregular rock is the best for building.* Mineral ores are not very common, but galena was formerly worked at Dimminsdale and copper ore is said to have been obtained in Calke Park. 8 There is not much doubt that the limestone underlies the other forma- tions at no very great depth in the district to the north of Grace Dieu between Ticknall and Breedon. In this area the beds are bent into a flat arch on the western side, while on the eastern side they are turned up nearly vertically by a large fault which appears to be a continuation of one of the Charnwood fractures. To the south the limestone becomes much thinner, and although it probably underlies most of the coalfield, it thins out further south. In a boring at Desford only a little over twenty feet were found. 4 Overlying the limestone there are some dark shales with thin beds of sandstone and limestone, which become more sandy in the upper part before they are succeeded by the massive grits above. These beds are exposed over the limestone at Dimminsdale and Ticknall ; they vary considerably in thick- ness, but at the former place are from thirty to forty feet thick. They are also seen at Calke, under the railway at Worthington, and at Grace Dieu, but at Breedon, Breedon Cloud, and Osgathorpe are hidden by overlying beds of Trias. MILLSTONE GRIT Although there is a considerable area covered by Millstone Grit just beyond the north-west border of the county very little of this formation is seen within the county itself. The principal outcrop is that surrounding the limestone at Dimminsdale, which is the southern portion of the larger mass beyond the county boundary extending to the Trent at Stanton-by-Bridge. Another small inlier of this rock comes up at Thringstone, and it also occurs at the foot of the Keuper escarpment at Castle Donington, but the beds are very obscurely seen, and it is doubtful to what age they should be assigned. The Millstone Grit of this area is but a very poor representative of this rock as it occurs in the northern part of Derbyshire. It consists of a series of sandstones and grits, which are coarse and conglomeratic in the lower part, but fine-grained and thin-bedded towards the top. Some of the beds are very massive, and have been extensively worked as a building-stone, but the beds are too soft to form the striking features that they do further north beyond Derby. From the soft sandy character of the upper part of this formation it forms good arable land, which in places is largely appropriated for market gardens. The water supply afforded by these rocks is good, and is utilized for many places in Derbyshire. An analysis of this lime is given in the above memoir. W. J. Harrison, Geol. of Lelc. and Rut. 16 . G " 1 ' *"" *TT? f Pr greSS f r I 94- P- '54- The details of this boring are ing memoir on the Leicestershire and South Derbyshire Coalfield. given 6
