In the basins of the Forth and Clyde the following subdivisions are well marked: (5) Upper Red Sandstone series (red and grey sandstones, fireclays, shales, marls); (4) Coal Measures (white and grey sandstones, dark shales, fireclays, coal seams, ironstones); (3) Millstone Grit (massive sandstones and grits, with fireclays, thin limestones and coal); (2) Carboniferous Limestone series - (c) sandstones and shales, with three or more seams of limestone; (b) sandstones, shales, coals and ironstones, but with no limestone bands; (a) sandstones, shales, fireclays, coals and iron XXIV.
Next in upward sequence is a thick mass of sandstones, grits and shales - the Millstone Grit series.
A small patch of Millstone Grit and Limestone occurs in the south of the county about Melbourne and Ticknall.
The beds above the limestone are shales and sandstones, sometimes reaching the true Coal-Measures, but rarely younger than the English Millstone Grit.
The Pottsville formation is chiefly clastic, and corresponds roughly to the Millstone Grit of England.
There was great volcanic activity during the deposition of the Calciferous Sandstone, Carboniferous Limestone and Millstone Grit series.
The Coal Measures repose upon the Millstone Grit; the largest area of these rocks lieson the east, where they are conterminous with the coalfields of Yorkshire and Nottingham.
The mineral wealth of Saxe-Coburg-Gotha is insignificant, small quantities of coal, lignite, ironstone and millstone being annually raised.
I Upper black shales with thin limestones (Pendleside group) connecting this series with the Millstone grit above.
Five well-contrasted types of scenery in Derbyshire are clearly traceable to as many varieties of rock; the bleak dry uplands of the north and east, with deep-cut ravines and swift clear streams, are due to the great mass of Mountain Limestone; round the limestone boundary are the valleys with soft outlines in the Pendleside Shales; these are succeeded by the rugged moorlands, covered with heather and peat, which are due to the Millstone Grit series; eastward lies the Derbyshire Coalfield with its gently moulded grasscovered hills; southward is the more level tract of red Triassic rocks.