12 A POPULAR SKETCH OP THE GEOLOGY 



Cloud Hills is for the most part completely dolomitised, or converted 

 into magnesian limestone, with a cellular structure running along the 

 line of the beds. The fossils, too, are all in the state of casts, but 

 they are always such as are characteristic of the mountain limestone, 

 as Spirifers, Productce, Enomphali, or Bellerophons. Breedon is 

 so traversed by faults and joints in various directions, as at first sight 

 to have its stratification almost obscured : this, however, by a little 

 attention, may always be perceived, and will be found to dip fifteen 

 degrees to the south of west, at an angle varying from thirty-five to 

 seventy degrees. The limestone of Grace Dieu is similar to that of 

 Ticknal, only particular beds of it being magnesian. These hills are 

 everywhere surrounded by level beds of new red sandstone, out of 

 which they rise abruptly towards the east, with the broken edges of 

 their beds sticking up into the air, and seemingly unconnected with 

 any other portion of the country. We shall, however, shortly be able 

 to connect their elevation with that of the slates of Charnwood 

 Forest. 



Cambrian Rocks. 



Of the rocks which, in other localities, lie immediately beneath the 

 mountain limestones — namely the old red sandstone and the silurian 

 formations — Leicestershire presents no example whatever. In South 

 Wales the old red sandstone has a thickness of upwards of 10,000 

 feet, and the silurian system which lies below it consists of four great 

 formations, each many hundred feet thick, and each stored with its 

 peculiar and characteristic fossils. In this county, however, no trace 

 of any of them is anywhere to be perceived. Of the next inferior 

 group of rocks, however, which, coming out from below the silurian, 

 form the slate mountains of Wales, Cornwall, and Cumberland, we 

 have, in Leicestershire, a miniature example in the hills of Charn- 

 wood Forest. This system of rocks is termed by Professor Sedg- 

 wick the Cambrian system, and he divides it into two great groups, 

 the upper and lower Cambrian, each having a very great thickness, 

 and each, in Wales, cor tainiug organic remains. To which division 

 of the Cambrian rocks we must refer those of Charnwood Forest, is, 

 in the absence of organic remains in that district, of course doubtful ; 

 Professor Sedgwick himself being unable to decide the point. The 

 discovery of the merest trace of shells, then, or other fossils in the 

 slates of Charnwood Forest, would be highly valuable. The rocks 

 themselves consist of every variety, from a coarse greywacke to a 



