Part 2

We have already mentioned that Berkshire may be divided into three natural divisions. The northern or Vale of White Horse district is for the most part rather low-lying ground, but there is a small range of hills along the course of the Thames or Isis from Faringdon towards Oxford. Badbury Hill, 530 feet above the sea, and Faringdon Clump, 445 feet, are quite prominent from a distance, and some of the other hills from Buckland to Wytham look imposing when seen from the river. Much of this district was to a large extent swampy and boggy ground in old days, and a part of it is still spoken of as "the moors" by the country people. Some of the village names end in "ey," suggesting that they were islands in the marsh district. Goosey and Charney are examples. A good deal of the district is stiff clay, and there is difficulty in getting a supply of good water, hence we find a number of towns and villages, like Wantage for instance, close to the chalk downs, where there are many springs.

The second or central division of Berkshire is the district of the chalk land. The downs of Berkshire are separated from the Chiltern Hills, which are the chalk hills of Oxfordshire, by the valley of the river Thames, whilst on the west the chalk downs run on into Wiltshire without any natural break. The chalk ridge rises sharply up from the Vale of White Horse, and a large part of the crest is over 700 feet above the sea. White Horse Hill attains a height of 856 feet, and the village of Farnborough is 712 feet above sea level. There is a general slope of the chalk surface downwards towards the south, so that even the high part of Lambourn Downs is well below the 700-feet contour line, and long and beautiful valleys run up from the Newbury district into the chalk downs.

The northern border of the chalk district is a well defined line; not so the southern border. The chalk gradually bends downwards underground and is covered by sand, gravel, and clay, so that in many places we find the upper part of the hills sandy or clayey whilst the valleys beneath them are chalk. Thus Bussocks Camp and Snelsmore Common near Newbury are situated upon a ridge of gravel, sand, and clay, but the road from Chieveley to Newbury in the valley below the camp runs for most of the way along a chalk valley, and the chalk extends all around, but underneath the sand, gravel, and clay. Hence there is no definite southern boundary to the chalk district, and there is a bit of chalk country near Inkpen. The projecting part of Berkshire, bounded on the south by a line drawn from Twyford to Maidenhead and on the other sides by the river Thames, is also mainly a chalk district.

The southern division of the county has in consequence no definite northern border, but a line drawn from Hungerford in the west to Maidenhead in the east will have very little of chalk district to the south and very little forest country to the north, and is consequently a good practical boundary between the second and third divisions of Berkshire.

The scenery of the southern division is quite different from that of the other two divisions. The country consists to a great extent of wide and flat table-land 300 to 400 feet above the sea, in which the rivers and streams have cut valleys. There are also extensive tracts of clay land, but the clay is often concealed under a few feet of gravel.

5. WATERSHED. RIVERS AND THEIR COURSES. LAKES.

With the exception of a small tract in the south-western corner the county is wholly drained by the river Thames and its tributaries; that is to say, with a very few exceptions, every brook and stream in Berkshire is more or less directly a tributary of the Thames.

The river Thames or Isis becomes the boundary between Berkshire and Gloucestershire near Lechlade, and it flows in an easterly direction over a clay country, keeping a little to the north of the ridge of limestone hills upon which the villages of Buckland and Hinton Waldrist stand. Near Appleton the river bends to the north, curving round the outlying patch of limestone which forms Wytham Hill, and being joined by the river Evenlode. The united streams soon take a southerly course, and a little below Oxford are joined on the north by the Cherwell. The river then crosses the limestone formation near Sandford, and curves round by Radley to Abingdon. From Abingdon the river pursues a somewhat serpentine course with a general south-easterly trend towards Benson, being joined on the north near Dorchester by the river Thame. A little south of Benson the river, now the Thames proper, enters upon the chalk formation, across which it flows in a southerly direction to Streatley, and then takes a south-easterly course to Reading. At Streatley the river valley is deep, with steep sides separating the chalk downs of Berkshire from the chalk hills known as the Chilterns. The illustration above shows the Berkshire downs in the distance and the valley of the Thames in the foreground.

At Reading the Thames is joined by the Kennet, and it is interesting to notice that the main stream adopts the direction of the tributary and flows with a north-easterly course to Wargrave, near which place the river Loddon meets it from the south, and again the direction of flow of the tributary is adopted, the Thames taking a northerly course past Henley. It is also of interest to observe that the river has turned away from the soft clays which form the ground south and east of Reading, and has cut a deep valley in the hard chalk from Wargrave onwards. Beyond Remenham the course of the river becomes easterly, and near Cookham it turns south and flows past Maidenhead to Bray.

Near Bray the Thames leaves the chalk over which it has flowed for some 40 miles and enters upon a clay country, making its way in a fairly direct line to Windsor, the one place in the district where a knob of chalk sticks up through the clay. Windsor Castle stands upon this knob of chalk. The course of the river from Bray to Windsor is on the whole south-east, and after a big curve north at Eton the course becomes more southerly, with another big curve near Old Windsor. At Runnymede House the Berkshire boundary leaves the river, which flows on to London and the sea.

The river Cole rises on the chalk not far from Ashbury, and flowing in a northerly direction joins the Upper Thames or Isis at the extreme western boundary of the county.

The river Ock rises on the chalk near Uffington, and flows down the Vale of White Horse to join the Thames at Abingdon.

The river Pang rises on the chalk not far from Compton, and flows in a southerly direction to near Bucklebury, where it turns eastward, passing through a beautiful valley by way of Stanford Dingley and Bradfield to a point near Tidmarsh. It then makes a sharp turn to the north and joins the Thames at Pangbourne. This lower part of the course of the Pang is worthy of study, for there is a continuous band of river alluvium along the valley from the Thames at Pangbourne to the Kennet at Theale. The source of the river, too, is well worthy of investigation. In dry times it will be found in the valley near Compton, but in wet seasons it is much further up in a branch valley towards East Ilsley.

The Lambourn also rises on the chalk near the place of that name, and it flows in a south-easterly direction and joins the Kennet close to Newbury. The Pang and the Lambourn flow in chalk valleys for the whole of their course.

The river Kennet rises in Wiltshire, enters Berkshire near Hungerford, and flows with an easterly course by way of Kintbury, Newbury, and Theale, finally joining the Thames close to Reading. It is a chalk river, and obtains a considerable amount of water from springs in the valley along its course.

The Emborne is not a chalk stream. It rises in the Inkpen district and flows in an easterly direction, forming, as we have seen, the county boundary for a considerable distance. Its course is almost parallel to that of the river Kennet, the two valleys being separated by hills or plateaux of clay, sand, and gravel. Near Brimpton the Emborne turns sharply to the north-east, and joins the river Kennet near Sulhampstead Bannister.

The Foudry Brook rises in a clay district of Hampshire, not far from Silchester, and runs by way of Stratfield Mortimer and Grazeley to the river Kennet near Reading. It is a small stream now, but there is a good deal of alluvium along its course, showing that it was of more importance in former times.

The river Loddon rises in Hampshire and enters Berkshire at the edge of Strathfieldsaye Park, its direction being northerly. Soon, however, it turns to the north-east and flows in a tolerably straight line to join the river Thames near Wargrave.

The Blackwater rises near Aldershot and reaches Berkshire at Blackwater Bridge, where, as we have said, the counties of Berkshire, Hampshire, and Surrey meet. From this point the river flows in a north-west or west direction and forms the Berkshire boundary for eight miles to a point near Little Ford below Farley Hill. The Blackwater then turns into Berkshire, running in a north-westerly direction to Swallowfield, where it joins the river Loddon.

There are no natural lakes in Berkshire, though there are the deposits of a former lake in the valley of the Kennet near Newbury.

There was formerly a sheet of water near Twyford named Ruscombe Lake, which had some claim to be called a natural lake, in that it was a low-lying bit of ground which was flooded owing to the absence of a good outlet. Its natural outlet was into the river Loddon, and there is a patch of alluvium extending from its site through Stanlake Park to that river. It was eventually drained by making a deep channel called the "Cut," draining a considerable area into the Thames near Bray. It has been asked why the river Thames did not follow the line of Ruscombe Lake and the Bray Cut, all soft clayey soil and low ground, instead of cutting the great and deep valley through the chalk by way of Wargrave, Henley, Great Marlow, and Maidenhead. The explanation probably is that the river Thames existed before any of these valleys, and that its course was determined by local features which have long since been destroyed by rain and streams, and by the river itself.

6. GEOLOGY AND SOIL.

Before giving further account of the physical geography of the county it is necessary to learn somewhat of its geology, as the physical conditions are to a large extent dependent upon geological structure.

By Geology we mean the study of the rocks, and we must at the outset explain that the term rock is used by the geologist without any reference to the hardness or compactness of the material to which the name is applied; thus he speaks of loose sand as a rock equally with a hard substance like granite.

Rocks are of two kinds, (1) those laid down mostly under water; (2) those due to the action of heat.

The first kind may be compared to sheets of paper one over the other. These sheets are called beds, and such beds are usually formed of sand (often containing pebbles), mud or clay, and limestone, or mixtures of these materials. They are laid down as flat or nearly flat sheets, but may afterwards be tilted as the result of movement of the earth's crust, just as you may tilt sheets of paper, folding them into arches and troughs, by pressing them at either end. Again, we may find the tops of the folds so produced worn away as the result of the constant action of rivers, glaciers, and sea-waves upon them, as one might cut off the tops of the folds of the paper with a pair of shears. This has happened with the ancient beds forming parts of the earth's crust, and we therefore often find them tilted, with the upper parts removed. Tilted beds are said to dip, the direction of dip being that in which the beds plunge downwards, thus the beds of an arch dip away from its crest, those of a trough towards its middle. The dip is at a low angle when the beds are nearly horizontal, and at a high angle when they approach the vertical position. The horizontal line at right angles to the direction of the dip is called the line of strike. Beds form strips at the surface, and the portion where they appear at the surface is called the outcrop. On a large scale the direction of outcrop generally corresponds with that of the strike. Beds may also be displaced along great cracks, so that one set of beds abuts against a different set at the sides of the crack, when the beds are said to be faulted.

The other kinds of rocks are known as igneous rocks, which have been melted under the action of heat and become solid on cooling. When in the molten state they have been poured out at the surface as the lava of volcanoes, or have been forced into other rocks and cooled in the cracks and other places of weakness. Much material is also thrown out of volcanoes as volcanic ash and dust, and is piled up on the sides of the volcano. Such ashy material may be arranged in beds, so that it partakes to some extent of the qualities of the two great rock groups.

The production of beds is of great importance to geologists, for by means of these beds we can classify the rocks according to age. If we take two sheets of paper, and lay one on the top of the other on a table, the upper one has been laid down after the other. Similarly with two beds, the upper is also the newer, and the newer will remain on the top after earth-movements, save in very exceptional cases which need not be regarded by us here, and for general purposes we may regard any bed or set of beds resting on any other in our own country as being the newer bed or set.

The movements which affect beds may occur at different times. One set of beds may be laid down flat, then thrown into folds by movement, the tops of the beds worn off, and another set of beds laid down upon the worn surface of the older beds, the edges of which will abut against the oldest of the new set of flatly deposited beds, which latter may in turn undergo disturbance and removal of their upper portions.

Again, after the formation of the beds many changes may occur in them. They may become hardened, pebble-beds being changed into conglomerates, sands into sandstones, muds and clays into mudstones and shales, soft deposits of lime into limestone, and loose volcanic ashes into exceedingly hard rocks. They may also become cracked, and the cracks are often very regular, running in two directions at right angles one to the other. Such cracks are known as joints, and the joints are very important in affecting the physical geography of a district. As the result of great pressure applied sideways, the rocks may be so changed that they can be split into thin slabs, which usually, though not necessarily, split along planes standing at high angles to the horizontal. Rocks affected in this way are known as slates.

If we could flatten out all the beds of England, and arrange them one over the other and bore a shaft through them, we should see them on the sides of the shaft, the newest appearing at the top and the oldest at the bottom. Such a shaft would have a depth of between 50,000 and 100,000 feet. The beds are divided into three great groups called Primary or Palaeozoic, Secondary or Mesozoic, and Tertiary or Cainozoic, and at the base of the Primary rocks are the oldest rocks of Britain, which form as it were the foundation stones on which the other rocks rest, and are termed Precambrian rocks. The three great groups are divided into minor divisions known as systems.

NAMES OF SUBDIVISIONS CHARACTERS OF ROCKS SYSTEMS

{ { Metal Age Deposits } { Recent { Neolithic ,, } Superficial Deposits { Pleistocene { Palaeolithic ,, } { { Glacial ,, } T { E { { Cromer Series } R { { Weybourne Crag } T { Pliocene { Chillesford and Norwich Crags } Sands chiefly I { { Red and Walton Crags } A { { Coralline Crag } R { Y { Miocene Absent from Britain { { { Fluviomarine Beds of Hampshire} { { Bagshot Beds } { Eocene { London Clay } Clays and Sands { { Oldhaven Beds, Woolwich and } chiefly { { Reading Groups } { { Thanet Sands }

{ { Chalk } { Cretaceous { Upper Greensand and Gault } Chalk at top { { Lower Greensand } Sandstones, Mud and { { Weald Clay } Clays below { { Hastings Sands } { { { Purbeck Beds } S { { Portland Beds } E { { Kimmeridge Clay } C { { Corallian Beds } O { Jurassic { Oxford Clay and Kellaways Rock} Shales, Sandstones N { { Cornbrash } and Oolitic D { { Forest Marble } Limestones A { { Great Oolite with Stonesfield } R { { Slate } Y { { Inferior Oolite } { { Lias--Upper, Middle, and Lower} { { { Rhaetic } { { Keuper Marls } { Triassic { Keuper Sandstone } Red Sandstones and { { Upper Bunter Sandstone } Marls, Gypsum and { { Bunter Pebble Beds } Salt { { Lower Bunter Sandstone }

{ { Magnesian Limestone and } { Permian { Sandstone } Red Sandstones and { { Marl Slate } Magnesian Limestone { { Lower Permian Sandstone } { { { Coal Measures } Sandstones, Shales { Carboniferous { Millstone Grit } and Coals at top { { Mountain Limestone } Sandstones in middle { { Basal Carboniferous Rocks } Limestone and Shales { { } below { { { Upper } } Red Sandstones, { Devonian { Mid } Devonian and Old } Shales, Slates and P { { Lower } Red Sandstone } Limestones R { I { { Ludlow Beds } Sandstones, Shales M { Silurian { Wenlock Beds } and Thin Limestones A { { Llandovery Beds } R { Y { { Caradoc Beds } Shales, Slates, { Ordovician { Llandeilo Beds } Sandstones and { { Arenig Beds } Thin Limestones { { { Tremadoc Slates } { Cambrian { Lingula Flags } Slates and { { Menevian Beds } Sandstones { { Harlech Grits and Llanberis } { { Slates { { { Sandstones, { Pre-Cambrian No definite classification { Slates and { yet made { Volcanic Rocks

In the preceding table (p. 29) a representation of the various great subdivisions or 'systems' of the beds which are found in the British Islands is shown. The names of the great divisions are given on the left-hand side, in the centre the chief divisions of the rocks of each system are enumerated, and on the right-hand the general characters of the rocks of each system are given.

Berkshire is now part of an island and is a long way from the sea, but there have been times when the arrangement of land and sea on the globe was very different from what it is now. Our district has during some periods been part of a continent, and in others it has been overflowed by the sea.

These changes in the distribution of land and water were due to movements of the crust of the earth, and very largely to movements of compression from the sides, causing folding of the strata of which the crust of the earth is composed.

After many and great changes, at a time geologically recent, but still long before the beginning of history in the usual sense of the word, the district now known as Berkshire rose above the sea for the last time.

Since that date deposits of clay, sand, etc., have been formed in our area, and their formation is indeed still going on to some extent, but though these are true geological deposits they are of no great thickness, seldom as much as 20 feet. They are, however, at or near the surface of the ground, and consequently exercise considerable influence on the character of the country. We will, however, leave them out of account for the moment and consider the deposits formed before the district finally rose above the sea.

These deposits are usually spoken of as forming the solid geology of the area, and the three divisions, into which as we have said Berkshire is divided, are characterised as follows:--

1. In the northern part of the county, including the Vale of White Horse, the geological strata are older than the chalk formation. 2. In the central part of Berkshire the chalk formation is at or near the surface of the ground. 3. In the forest country of south and east Berkshire, the surface is formed of geological formations newer than the chalk, but the chalk is always to be found underground if one goes deep enough.

If we look at a sectional plan of geological strata we shall see that none of the formations which come to the surface in our county are of any great antiquity, but somewhere deep down, say over a thousand feet below us, there is a platform of much older rocks, upon which those that come to the surface rest in an irregular manner. What these old rocks may be we do not know, but probably New Red Sandstone and possibly beds of coal may occur amongst them.

Speaking generally, we pass from older to newer geological formations as we go from the north-west towards the south-east, and we find that the Oxford Clay is the oldest formation which comes to the surface in Berkshire.

The Oxford Clay forms a strip of low land along the banks of the Isis from the Cole to the Cherwell near Oxford. It was originally mud deposited in a sea which extended over a great part of England. It is dark coloured, often shaley, with a little clayey limestone. A large oyster is one of its common fossils. Its thickness is about 450 feet, and it is not a water-bearing formation. The Oxford Clay dips underground to the east and is covered by newer rocks, the first of which is the Corallian.

The Corallian forms a very well-marked band running across the county from the Cole to the Thames. Wytham Hill is formed of it, and Shrivenham, Coleshill, Faringdon, Buckland, Fyfield, Appleton, and Cumnor are situated upon it. It is essentially a calcareous formation with some hard limestone beds, and has a thickness of from 50 to 80 feet. It was formed in the sea; probably a shallow sea with shoals, sand, and coral banks. Fossil corals are abundant, and many specimens of Ammonites and other marine shells are to be found. There are some good examples of these from Marcham in the Reading Museum. Supplies of good water may often be obtained from this formation. The Corallian beds are quarried for building stone and road material in many places.