The beds of clays and seams of coal make up what are called the 'Coal Measures'. These in their turn rest upon a foundation of hard rock, harder than any we have yet examined, called Millstone Grit or Gritstone. Boys who live in the hilly parts of East Cheshire are very familiar with it, for very probably the houses in which they live and the churches and chapels where they worship have been built of this stone. It is composed of coarse sand and grit, and, like the red sandstone, is a waterlaid deposit several thousand feet in thickness. The Pennine Hills, on the borderland of Cheshire and Derbyshire, are covered with Millstone Grit, which has been thrust upwards by the crumpling and arching of the rocks beneath it.
Below the Gritstone are still older rocks of a different character called the Limestone series. The uppermost beds contain layers of a sandy substance called Yoredale sandstones. Mixed with them are layers of shale, a dark bluish grey clay that crumbles into thin fragments when crushed with the hand, and thin seams of limestone and, occasionally, of coal. These are the oldest rocks that are found anywhere in Cheshire. You may see them in the hills east of Macclesfield and Congleton and the higher parts of Longdendale. Below these beds is a mass of Mountain Limestone which has been forced upwards into an arch by tremendous pressure of rocks from either side, and has lifted up the Gritstone above to a height of nearly two thousand feet. In this way the highlands of East Cheshire, and indeed the whole of the Pennine Chain, have been formed. The Mountain Limestone, which consists almost entirely of animal remains, especially shells and corals, extends right under the highest hills of Cheshire, and comes to light in the cliffs of the beautiful dales of Derbyshire. Only at one spot, a quarry near Astbury, does it appear at the surface in Cheshire.
The Coal Measures, Millstone Grit, Yoredale sandstones, and Mountain Limestone make up what geologists call the Carboniferous or Coal-bearing series, so called because in England our chief supplies of coal are obtained from this group of rocks.
But we should have to dig deeper even than the Mountain Limestone before we could reach the original surface of the earth in Cheshire. Long ages ago, ages so distant that not even the most learned men of science can reckon them, our earth was a globe of fiery molten rock. As the surface gradually cooled it became wrinkled, as a baked apple will when taken from an oven. Water collected in the hollows into which fragments of rock were washed down from the ridges, and thus the waters were raised and formed into seas and lakes. But we shall not find any of these rocks in Cheshire, though you may see them in great masses in the mountains of Cumberland and Wales, where they have been forced upwards by the violent movements always at work in the interior of the earth. It is of these molten rocks that the mass of stone which was brought by the ice from Cumberland and left on Eddisbury Hill is composed.
CHAPTER IV
EARLY INHABITANTS OF CHESHIRE
A few years ago some workmen digging on the high ground of Alderley Edge came across a number of flint stones, which from their shape and the marks of chipping upon them had clearly been fashioned by the hand of man. Some of the flints were shaped like a knife blade with a sharp edge on their entire length, and others of a more or less oval shape had a keen edge on one of their curves. The former were the knives with which the earliest men of Cheshire cut the flesh of animals for food; the latter were the scrapers with which they removed the flesh from the bones or from the hides that provided them with clothing.
Flints, however, are not naturally found in any of the Cheshire rocks; they must be sought for in the districts where chalk hills abound. Clearly therefore these men must have brought their tools and weapons with them when they first came into Cheshire from the east or from the south. Afterwards, no doubt, they bargained for them, giving skins and furs in exchange.
Men first made their homes in Cheshire when the glaciers of the Great Ice Age retreated northwards and the climate became more suitable for human habitation. A flint arrow-head found during some excavations at Clulow Cross near Wincle, tells us that men lived then by hunting, depending for their food on the flesh of wild beasts. They lived in caves or in holes dug in the ground. The roughly-chipped stone axe in the Grosvenor Museum was made by these men.
The Flint men, or men of the Old Stone Age, probably came originally from the mainland of Europe to which Britain at that time was joined, the North Sea and English Channel being then dry land. The reindeer, the mammoth, the wild ox, and packs of hungry wolves and hyenas roamed over Cheshire in those days.