The Physical Geography and Geology of the County of Leicester

Chapter I. Physical Geography

An account of the physical geography of a small artificial division of a country cannot but include a number of details more or less characteristic of the whole country. Thus the hill systems, the river systems, the plains and valleys, the natural drainage, the state of the surface and of the rocks beneath the surface, the climate and the meteorology, and the natural distribution of animals and plants in Leices tershire, are all matters closely connected with those of England generally, and especially of the Midland counties. In respect of these, however, it is unnecessary to enter into any detail. We are concerned only with the county, and to what is found within its artificial boundaries we must limit our remarks. It might indeed seem, that a chapter devoted to the physical geography is hardly called sol as part of the natural history of the county ; but this is not the case, for, although in many districts of equal area there would be nothing special in the natural history and geology, there are few counties of England that better deserve separate notice than the county of Leicester.

Leicestershire possesses many peculiarities that justify this statement. It con sists chiefly of undulating ground, but out of this ground rises a system of hills, of no great absolute or relative height, but remarkably characteristic, and geologically quite exceptional. Connected with this curious chain of low elevations — mountainous in their aspect and extremely picturesque — is a rich mineral district ; and here again are the physical features exceptional. Small hills, of a rock totally different from that which prevails around, stand out strangely and prominently in various places ; and derived from and connected with the country thus broken is a special system of natural drainage. Dependent on these physical features, and yet more on the nature of the rock beneath, the surface affords a singular variety of soils, some very poor others very rich ; and within the district is an unusual wealth of species of plants.

The animal kingdom is also richly represented. It is one of the peculiarities of Leicestershire that it contains the easternmost of all the rocks of the nature of granite found in England, and that the rocks of this kind here are not connected at the surface with rocks of similar mineral composition further west. Within this county there is a minute detached area of granite and syenite, surrounded by slates, and covered by coal-bearing strata which are to all b2 XATUEAL HISTOEY OF LEICESTEESHIEE. 4 appearance isolated. To the east, south, and north more modern rocks come in. These are repeated beyond the western borders of the county. The picturesque features of Leicestershire are greatly affected by — they are, indeed, altogether dependent on and traceable to — its physical geography and geological structure.

Charnwood Forest, an old and once densely wooded tract in the north-west of the county, is the district of granite and slate hills, and the valleys between the hills are often filled up with the red marl. The Ashby wolds and the broad spaces in that part of the county, round the ancient town of Ashby-de-la- Zouch, are equally characteristic of the coal measures. Breedon Hill is a strange isolated lump of magnesian limestone, and the vale of Belvoir is a singular and most picturesque hollow, which, seen from the heights on which stands Belvoir Castle, is exceedingly striking and suggestive of geological changes. Situated very nearly midway between the Irish Channel and the German Ocean, Leicestershire might be expected to escape the heavy rains of the western coast and the piercing chill of the east winds ; and in some measure it does so.

Nowhere lofty enough to attract clouds, but having its surface undulating so as to admit of natural channels to carry off the water that falls from the skies as rain, this county has small streams in abundance and numerous springs, but no lakes, and few pools, and only one river of importance. On the hills, however, where the rough broken granite still stands out weathered, broken, and grand, and where once thick forests were a shelter to numerous wild animals as well as to many a bold outlaw, there are now only a few picturesque nooks. Everywhere the hand of man is seen creeping gradually onwards with the plough, occupying all the slopes and penetrating the inmost recesses. Although the country is still quiet and retired, and only thinly peopled, one realises with difficulty the forest character, and there can hardly be a doubt that in former times the larger extent of wood retained much of the water that now runs off, so that the streams are both diminished and are more regular.

The Trent, a bold and rapid river, the recipient of most of the county streams, rarely now overflows its bed or alters its course, though formerly it must have done so every season. The Soar, a smaller river but a chief tributary of the Trent, has in like manner become more regular and smaller. But the old character remains, and it is not easy for those unfamiliar with the district to understand the amount of beauty and wildness in this little tract, whose highest elevation is but a few hundred feet, whose lands are for the most part under cultivation, in which excellent roads are to be found in every direction, and even whose quarries, though no doubt large and fine, and working granite, limestone and slate, are hardly extensive enough at present to affect the general landscape, though it is not unlikely they will do so in a few years.

The chief elevation of the county is Bardon Hill, a fine rugged mass of granite, nearly covered with beautiful trees, rising about 853 feet above the sea, but not more than 250 feet above the new red sandstone plain. Bardon Hill is one of a number of granite hills which are grouped round the slate district of Charnwood PHYSICAL GEOGEAPHY. 5 Forest, as Cliff Hill, Markfield Knoll, and some hills near Groby to the south. The lower ground in Bradgate Park to the south-east, and the hills called Buddon Wood and Mount Sorrel at some distance to the east, are also localities marked by the presence of granitic rock, though in a somewhat less prominent manner. Amongst these granites there are tracts of slaty rock, the harder portions of which rise above the general level of the district, and form hills of which Old John in Bradgate Park is one of the principal.

The Rice rocks and the rocks of Peldar Tor near Whitwick are examples of peculiar and picturesque forms assumed by hard rock of other kinds. They more resemble the well-known Stiper Stones of Shropshire than any of the rocks in the neighbourhood. There is much beauty of a varied character in the parts of Charnwood Eorest broken by the granite. That this is owing to anything more than denudation, the softer rocks being removed and the harder left rough and jagged, is not likely, but the effect is almost sub-alpine, and the contrasts of scenery afforded often very striking. Erom the top of Bardon Hill the view eastwards across the slate hills and the valleys that run up between them is both pleasing and very extensive, while the view westward across the Ashby coal-field ranges yet more widely, reaching to the Malvern Hills.

Part of the intermediate landscape partakes of the dull character that often marks the presence of a mineral district. Erom Old John in Bradgate Park the view is even more pleasing than from Bardon, but it has less dependence on the physical features, and is far less extensive. Beacon Hill is another principal elevation. There is still a good deal of rich woodland scenery in Charnwood Eorest, although less than in ancient times, and it is chiefly limited to the granitic hills and parks, the valleys between being under cultivation. Breedon and Cloud Hills in the north-west of the county are detached elevations of a very different character. The former rises abruptly out of the plain, and has no doubt been a very picturesque object in its natural state. Consisting entirely of limestone, it has for a long time been largely quarried, and, half the hill being now gone, the whole character is altered.

The limestone quarries are fine, but the hill is almost grotesque. Cloud Hill is clothed with wood, but is low. The view from the church on the top of Breedon Hill is very interesting. The physical features already described are due to very striking geological peculiarities in the structure of the district that will be considered in detail in the next chapter. Those of the rest of the county are due to the more regular geological sequence, and they correspond with the appearances and condition of the adjacent counties. Thus in the north-eastern district we have the ridge on the extremity of which Belvoir Castle is placed. It is a fine and even grand position, overlooking what is called the Vale of Belvoir. The sides of this hill or ridge are terraced. It belongs to the lias, but is bolder than is usual in that formation.

Besides this remarkable position, admirably suited to the noble residence constructed upon it, there are several adjacent hills, of which Blackberry Hill and Stathern Hill are the chief. South of these, where the marlstone, a sandy deposit in the lias, gives opportunity, there are hills of some interest; of these Billesdon Coplow is the most remark able. Besides these again there are lower hill ranges, and the whole county is broken and pleasantly undulating. The natural drainage of Leicestershire is by a considerable number of small streams, taking their origin in the hills and high ground of Charnwood Eorest, and proceeding thence by numerous rills and rivulets running through the valleys and dells between the harder syenites and more easily weathered slaty rocks. At the foot of these hills, and also in various places in the valleys, springs break out.

The smaller streams on the east side of the forest collect and unite in a broad valley of denudation, through which the river Soar runs ; those to the north fall directly into the Trent, crossing in some places part of the wide alluvial valley of that river ; those to the west, from Snibston and Bardon, fall into the Anker, and are by that stream conducted into the Bristol Channel, forming part of the basin of the Severn. The southern streams also enter the Severn. The Trent, which runs along a part of the northern edge of the county of Leicester, is a river quite as interesting for its marked physical features and charac teristics as for its historical recollections. It is a river of considerable magnitude, running through a broad alluvial valley occasionally widening out where it receives its principal tributaries.

This occurs beyond Kegworth, where the Soar enters it through a space that might almost be called a delta. Receiving by far the principal part of the drainage of Charnwood Eorest by a number of streams at present small, and receiving also the drainage of a considerable district by the Wreake entering near Syston, the Soar is an important stream, and subject to sudden and rapid changes. In former times, however, before the country was drained and cultivated, and when there were still forests of large extent, the floods of the Soar were certainly much more considerable, and must have been sufficient to alter the bed of the river from time to time. The alluvial bed is everywhere nearly a mile wide, and the deposit is of great thickness. This large and constantly varying tributary entering the Trent has greatly influenced that river in its course eastwards.

Another smaller stream also flows into the Trent from Leicestershire, crossing and draining the Ashby coalfield, and entering the Trent valley near Donington Park. The Soar is the largest of the true Leicestershire rivers, and receives a large number of tributaries ; four of them belonging to the drainage of Charnwood Eorest. Erom its sources in the south, as far as Leicester, it is a small and unimportant stream, though fed by several rivulets. Up to that point also it runs through a narrow valley. Beyond Leicester it assumes greater importance, and is navigable thence to its junction with the Trent, though not without much aid from canals and other industrial works. Its waters being thus regulated, it is now little exposed to floods and those sudden changes which have in former times affected it.

It is however an interesting study to the physical geographer, as it passes the edge of the Charnwood Eorest district. If not kept within artificial bounds its course would still be wild and mischievous, and this possibility may explain some of the anomalous conditions of its bed. PHYSICAL GEOGRAPHY. 7 The Eye entering the Wreke, and so coming into the Soar, is one of the streams draining the lias and other rocks occupying the parts of the county east of the Soar. Though entering the Soar, and thus ultimately carried by the Trent eastwards into the Humber, the original course of this and the other streams draining the secondary rocks is towards the west. They thus cross the strata at right angles to their strike and on the rise side of their dip. This, though not unknown elsewhere, is still to some extent an exceptional phenomenon.

There is another principal stream, the Meare, fed by the Sence, taking its rise in the coal-field of Ashby, on the overlying sandstone, and running westward, but also ultimately reaching the Trent. These rivers are not large, and seem less subject to change than the eastern streams. A large part of the whole drainage of the county thus belongs to the eastern water-shed of England, as indeed, geologically, might have been anticipated ; but we have pointed out that most of it does so only after having traversed the strata at right angles to their dip. The Soar is the only large stream that strictly belongs to the county. It both rises and falls into the Trent within the county, and the two rivers at their junction afford much matter for observation. Indeed the physical history of the course of the Soar, including both its eastern and western tributaries, affords a clue to the geological history of the district.

The following are the tributaries to the Trent, either directly or indirectly, which take their rise in or traverse the county of Leicester. (1.) The Deven, a small stream in the north-eastern extremity of the county, rising apparently at the foot of the upper Has, and running northward out of the county. Re-entering, it forms for some distance a boundary, separating Leicestershire from Nottinghamshire. It then enters the latter county and joins the Trent at Newark. It is joined by the Smite after it has left the county. The Smite rises in Leicestershire. (2.) The Eye, a tributary of the Wreke. Several small rivulets combine to form it, some of which rise in Rutlandshire, and others in Leicestershire. It enters the Wreke at Melton. (3.) The Wreke. A small stream coming in from Holwell is called the Wreke, after its junction with the Eye.

Under the name of Wreke the combined streams run westwards to the Soar, which it enters at Syston. It has several small tributaries, chiefly from the east, and drains a large part of the lower lias. (4.) The Soar has been already described. It drains Charnwood Eorest by many tributaries. (5.) The Mease and the Sence have also been alluded to. The former rises near Ashby-de-la-Zouch, but has its chief course in Derbyshire. It receives several tributaries, of which the Sence drains a part of the new red sandstone. Of the other streams there are few that are important. The Welland, in the south-east of the county, after receiving two or three tributaries, all rising in Leicester shire, passes out of the county, and finally enters the German Ocean at the Wash on the Lincolnshire coast. The Southern Eye is the name of one of these feeders.

The Avon rises in the county of Leicester, and forms its southern boundary for a few miles. It then flows into the Severn and enters the Bristol Channel. The Swift, a small stream also rising in the county, enters the Avon after joining the Dove, in Warwickshire. "It thus appears," says Mr. Curtis, in his Topographical History ofthe County of Leicester, " that springs arise in various parts of Leicestershire forming brooks, rivulets, and rivers, which finally terminate in the sea by the Humber to the north east, in the Wash between Norfolk and Lincolnshire to the east, and by the Severn towards the south-west. It may hence be inferred that Leicestershire must be on the highest elevated land, not actually hilly or mountainous, in the kingdom. There are no natural rivers which flow into the Dee or Mersey to the north-north west, into the Thames to the south-east, or the English Channel to the south ; in all these directions a water conveyance and communication is maintained by artificial canals."

Let us now proceed to a more extended consideration of the valley of the Soar, which traverses the whole of the county from south to north, and in great part separates the lias from the new red sandstone, the low escarpment of the lias rising generally but a short distance to the east of this valley, although it is partly cut through the gravels. Although somewhat geological, the following account of the valley, published by Mr. James Plant of Leicester in The Geologist for 1859, bears more directly on the physical geography of the district than on its geology, and therefore properly appears in the present chapter. " This valley, from its commencement in the neighbourhood of Lutterworth to its termination at Red Hill, where it joins the great Trent Valley, has been formed by the denudation of the lower lias, the upper new red marls, and the Keuper sandstone.

The denuded materials, ground and mixed together, are piled up on the sides of the valley to a depth in many places of 120 feet and upwards. Bones and teeth of ox, deer, horse, &c. are very frequently met with whenever the alluvial soil of the valley is excavated, especially near the present river-bed, but the teeth of elephants (which belong to an older period) have all been found in the drift, clays, and gravels that flank each side. In the neighbourhood of Barrow the lower lias has been denuded to the extent of from 160 to 200 feet, as shown by some remaining outliers of that formation. " The altitude of the valley above the sea-level at Barrow is about 180 to 200 feet, and its width from the escarpment of the marlstone or middle lias on the north-west to the slopes of Charnwood on the south-west is about seven or ei^ht miles.

Barrow lies near the centre, and in the neighbourhood of that place the drift-clays and gravels immediately covering the lower lias vary from 6 to 20 or 30 feet." There are few large pieces of water in Leicestershire ; and indeed almost the only pools of any importance are the deep, dark, gloomy waters of Groby, and the little pool of Langley Priory. The former is about forty acres in extent, but though small it amply repays a visit. In the middle is a small island ornamented PHYSICAL GEOGRAPHY. 9 with trees and shrubs and sheltering many species of water-fowl. In summer it is not unfrequently the resort of sea-gulls and a species of tern, while the heron is often seen wading along its shallow margin in search of prey. This pool contains numerous fresh-water fish, including pike, perch, bream, dace, roach, gudgeon, eel, tench, &c. The lake is surrounded chiefly by granite, which is quarried in the immediate vicinity.

The lake at Langley Priory is a picturesque sheet of pure clear water in a natural hollow. The climate of the county of Leicester differs now but Httle from that of other parts of the middle of England. Somewhat more excessive than that of the west coast, it is in some respects more pleasant than that of counties on the low east coast of England. More rain falls within it than in some of the adjacent counties. It is exposed to electric storms, but seems to have escaped most of those terrible cyclones which of late years have ravaged much of England. Its central position protects it from these disturbances. The sanitary condition is excellent, and the county is decidedly healthy. This is attributable partly to the facility with which all the water falling as rain is enabled to run off and escape, and partly to the absence of extensive flats and large sheets of water. The air in Charnwood is especially clear and pleasant, and highly salubrious. C:

Chapter II. Descriptive Geology Of The Earliest

PERIOD— SLATES AND PORPHYRIES OF CHARNWOOD FOREST. The descriptive geology of Leicestershire possesses peculiar and very remarkable interest and unusual variety. It exhibits (1) a series of metamorphic rocks of great age associated in a singular and instructive manner with porphyritic rocks ;* (2) a peculiar and typical development of rocks of the lower part of the carboniferous system, together with an important overlying coal-field ; (3) small but tolerably weU-defined Permian breccias ; (4) an interesting development of the trias in which the Keuper or upper marls are especially shown ; (5) an admirable exhibition of the lower members of the lias, both of the lower limestones and the marls ; (6) part of the lower oolite; and (7) in addition to these older rocks a large covering of glacial drift and other aUuvial and comparatively modern deposits.

At one period of its long and changing history it is certain that volcanic disturbances have occurred in the district under consideration, giving thus an amount of completeness to the sequence of rocks very rarely met with in so small an area. These volcanic rocks, however, have nowhere and at no time reached the surface. As in these chapters a mere technical and detailed account of geological facts would be out of place— such detail belonging rather to the history of the geological survey of England than to an account of the county of Leicester, I shall endeavour to communicate general views rather than the special facts on which such views are based. I ought, perhaps, to inform the reader at the outset, that in these views I am guided quite as much by the examination and observation of rocks of the same kind in other parts of England and the world as by the mere localities in the county.

If, therefore, in speaking of them, I seem to diminish their importance and treat them as small and of little account, it is so only by comparison, for there are few districts where so much that is instructive can be seen within a few daYs' geological work as the district of Charnwood Eorest and the country adjacent To the geologist this small tract of land and the phenomena presented there are crowded with facts, and are in the highest degree suggestive of inferences Re garded and examined with preconceived notions of the structure and composition of granite, the curious assemblage of porphyritic and slaty rock there exhibited has been hitherto described as offering great complication and requiring the introduction of a number of almost impossible disturbances and frequently repeated faults.

In- • By the term porphyritic rocks is here meant all those granites, syenites, greenstones, &c. which consist essentially of crystals embedded m a base. The nature of the base and the crystals varies exceedingly trusions of molten syenite and porphyry have been regarded as inevitable. These indeed have been described in one of the principal geological accounts of the dis trict yet published as " showing unmistakeably in their structure the action of intense heat;" and the district is said to have a poor soil "as might be expected from its volcanic nature."* Elsewhere we read of " rocks caUed porphyry and syenite ; these we know to be igneous rocks, or to have been once in a state of fusion by intense heat."t As I shall endeavour to present the reader with a very different view of the case, I have thought it right to aUude to these remarks.

We may without inconvenience divide the geological history of the district into four periods. The first of these terminated with the elevation of the syenites and slates before the commencement of the carboniferous Hmestone ; the second with the deposit of the Permian breccias ; and the third with the latest secondary deposits of the county, which are some poor representatives of the inferior ooHte ; the fourth period includes that of the later tertiaries and the northern drift, and brings us to the present time. The intervals between these periods, except between the second and the third, are very strongly marked locally, and all possess good geological landmarks. The duration of each period can be measured only by the suc cession of events, but must unquestionably have been very great. Some indication of this will be seen in the following pages.

Slates and Porphyries. These belong to the earliest geological period of the first of the divisions alluded to at the beginning of this chapter. To understand them requires careful and close attention, and the study of them in the field affords many valuable facts and suggestions on the subject of metamorphic geology. That the rocks of Charnwood Eorest, hitherto described as igneous, are strictly metamorphic, — that the syenitic and porphyritic rocks there exhibited really alternate with the slates, and are strictly contemporaneous, — that the whole series therefore is nothing more than a series of altered stratified rocks with few intru sive or trappean rocks, is a suggestion that may startle the geological reader, as it seems to contradict, in a matter regarded as beyond question, all the opinions of those geologists who have hitherto described the county.

I venture, however, to put it forward as based upon a considerable amount of evidence, and as explaining, in the only rational way that the subject admits of, the peculiar anomalies that have hitherto puzzled all local observers, and that have been left without much elucidation by the authorities of the Geological Survey. To avoid much repetition and frequent explanation, I must be permitted to make use of the terms meta morphic, igneous, and porphyritic, in such senses as seem most consistent with the present state of geology. They are terms still used vaguely by geologists, and perhaps are not altogether capable of being strictly limited * White's Directory. Article on the geology of the county by the Rev. W. H. Coleman, p. 78. ■f* Potter's Charnwood Forest. Article on Geology by J. B. Jukes, Esq. Appendix, p. 21.

C to particular rocks in the present state of science. I understand, however, by igneous rod; a rock that has certainly been reduced to its present state by igneous fusion, but I do not admit as sufficient proof of fusion that the rock is crystalline, that it seems to be intrusive, that its composition is almost identical with that of lava, or that it underlies all other known rock, and contains neither trace of stratification nor fossil remains. Lava is the type of igneous rock ; basalt of the ordinary kind and pumice are conditions of lava, the one compact, showing the result of lava poured out under heavy pressure, and the other spongy, the result when the lava is much mixed with air. Granite, syenite, greenstone, and the various rocks called pophyry, are not in my use of the term igneous.

Some of them may have resulted from erupted rocks diffused through and arranged by water. Metamorphism I understand to mean a change, whether small or great, that has taken place in a rock after it has once been formed, and while subject to the influences that modify and transform all substances buried deep in the earth for a long time. In its general action metamorphism converts clay into slate, limestone into marble, and sand into quartz ; but it does more it produces large cracks and open spaces in rocks, and fills these subsequently with new minerals. It also produces in some cases a complete re-arrangement of the atoms of a rock, and thus may convert mixtures of clay, sand, and other substances into granite, syenite, and greenstone. Porphyry is another geological term that in its old sense was limited to one rock, but is now applied to describe a structure.

All rocks that contain crystals embedded in a base are called porphyries, and thus the term may be vised properly in those doubtful cases where rocks appear to be igneous but may be metamorphic. With these somewhat technical remarks, addressed more particularly to the geological reader, I now proceed to describe the metamorphic geology of Leicestershire. The parts of Leicestershire in which metamorphic rocks appear at the surface are chiefly included in a belt of country eight miles in length from north-west to south-east and about five miles wide. There is one principal outlying mass at Mount Sorrel and Buddon Wood, and several of much smaller magnitude at various places to the east and south of the principal mass. It is certain that these are connected, and that the red marls at the surface conceal much of the same kind of rock which lies at no great depth for several miles in these directions.

Towards the north-west the metamorphic slates are succeeded by greatly altered and dolomitised limestones appearing in several small hills, while to the west comes in the important coal-field of Ashby-de-la-Zouch, extensively and profitably worked, and containing much valuable coal. There is a sheet of basaltic rock in this coal-field, erupted since the deposit of the carboniferous series, and connecting the district with some volcanic vent at a period long subsequent to the deposit of the slates and coal measures. There is no evidence that this eruption was subaerial. The whole mass of metamorphic rock below the carboniferous limestone of the neighbourhood (which is generaUy dolomitised, but contains numerous fossils,) is without any satisfactory evidence as to its age. Scarcely any indications of organic existence have been found in it, the few exceptions being certain markings on the slate rocks in a quarry near Woodhouse Eaves, which will be alluded to in another chapter.