Records of Woodhall Spa and Neighbourhood Part 6

117) says: "The Boulder clay is bedded against the slope of the chalk, shewing that this escarpment had retired to its present position in pre-glacial times." By what precise process this was effected must be left to our savants to decide; but the remarkable fact remains, that a solid stratum, or rather series of allied strata, from 500ft. to 1,000ft.

in thickness, has, by one process or another, been wiped out of existence, over the large area now coated by the Kimeridge clay. Through ages of enormous length the chalk was forming as the bed of a sea; a deposit consisting of inconceivable myriads of beautiful minute sh.e.l.ls, mainly of the foraminifera, which can be detected by the microscope; and its destruction probably occupied as long a period as its formation.

Mr. Jukes Brown, whom I have just quoted, says: "The Wold hills must have been, in some way, exposed to a severe and long-continued detrition, when erosive agencies were very active." Active, indeed, they must have been, to efface from an area so extensive a solid formation from 500ft. to 1,000ft. in thickness. And this boulder clay, as Mr. Jukes Brown further observes, has forced its way up the sides of the chalk, in places, to a height varying from 300ft. to 400ft.

The Oxford clay, which lies next below the Kimeridge, is a deep sea deposit, dark blue, with brown nodular stones; some of the fossils found in it are Nucula Ornata, Ammonites Plicatilis, A. Rotundus, Cucullaea, Gryphaea Dilatata, Leda Phillipsii, Annelida Tetragona, and A.

Tricarinata, Avicula inequivalvis. {94b}

Kellaway's rock, which lies just below, so called from a village in Wilts.h.i.+re, near Chippenham, is a mixture of yellowish and buff sands, with brown and buff sandstone. The chief fossils are Gryphaea Dilatata, and G. bilobata, Belemnites in abundance, and Avicula Braam-buriensis.

{95a}

The Cornbrash, which succeeds (so called also from a district in Wilts.h.i.+re, favourable to corn), is a light grey, fine-grained limestone, often so hard as to need blasting. It abounds in fossils. Among them are Avicula Echinata, Ostraea Sowerbyi, Clypeus Ptotii, Ammonites Macrocephalus, A. Herveyi, Nucula Variabilis, Astarte Minima, Trigonia (of four kinds), Modiola (of four kinds), Myacites (five kinds), Cypricardia, Corbicella Bathonica, Pholadomya (two kinds), Cardium (three kinds), Pecten (six kinds), and several more. {95b}

The great Oolite (so named from the Greek Oon, an egg, referring to the number of small stones, like fish-ova, found in it) is divided into Oolite clays and O. limestone. The clays are mottled green and bluish, with bands of ironstone, and concretions of lime. They indicate a shallow sea, as contrasted with the Oxford clay. Fossils are not numerous, but Rhinconella Concinna, Gervillia Cra.s.sicosta, Modiola Ungulata, Ostraea Gregaria, O. Sowerbvi, O. Subrugulosa, Perna Quardrata, Trigonia Flecta, and Palate of Fish are found. {95c} These beds correspond to the so-called Forest Marble of the South of England.

The Oolite limestone beds consist of white soft limestones, having at intervals bands of marly clay. This formation burns well, and makes good lime. Its chief fossils are Serpula, Rhynconella, Terebratula, and T.

Intermedia, Avicula Echinata, Corbicella, Lima Rigida, Lucina, Modiola Imbricata, Myacites Calceiformis, Mytilus Furcatus, Ostraea Sowerbyi, Pecten Vagans, Pteroperna plana, Trigonia, T. costata, T. flecta, T.

striata, T. undulata. {95d}

The Estuarine deposit, underlying the great Oolite limestone, is composed of light blue, green, and purple clays, intersected by soft bands of sandstone, and having at its base a band of nodular ironstone. It is not very fossiliferous, but the following are found:-Rhynconella Concinna, Modiola Imbricata, Ostraea Sowerbyi, Monodonta. {95e} The sandstone bands contain plant-markings in considerable numbers. As its name implies, this formation was produced as the bed of an estuary or tidal river.

The next lower formation is the Lincolns.h.i.+re limestone. This enters largely into the making of what is called "the Cliff," which is the high land running south from Lincoln (visible from Woodhall) to the west of the Witham Valley and the Fens. It is a hard building stone, though once the muddy bed of a sea. It is sub-divided into the Hibaldstow and Kirton beds, so called because these strata are exposed in those parishes.

Dipping to the east, it underlies the Fens and other upper strata to be found in the Woodhall well. It abounds in fossils, there being as many as 340 species cla.s.sified, {96a} and consists, indeed, very largely of the hard parts of sh.e.l.ls and corals compressed into a solid ma.s.s. To a Lincolns.h.i.+re person, it is sufficient to say of this stone that our grand Cathedral is mainly built of it. We can only give here a few of the more frequent species of fossils:-Three kinds of Echinus, Coral (Thecosmilia gregarea), Serpula socialis, Lima (five kinds), Ostraea flabelloides, Pecten (two kinds), Hinnites abjectus, Astarte elegans, Cardium Buckmani, Ceromya Bajociana, Cyprina Loweana, h.o.m.omya Cra.s.siuscula, Isocardia, Cordata, Rhynconella (four kinds); among the bivalves are Avicula Inequivalvis, and A Munsteri, Lima (three kinds), Lucina Bellona, Modiola Gibbosa, Mytilus Imbricatus, Pholadomya (two kinds), Trigonia costata; of univalves, Natica (two kinds), Nerinea Cingenda; of fishes, Strophodus (two kinds). {96b} This is a most useful stone for building purposes.

The so-called "Lincoln stone" is largely used in our churches; whilst the "Ancaster quarries," which also belong to this formation, are famous.

The commissioners appointed in 1839 to report on the building stones of England, for the new houses of Parliament, stated that "many buildings constructed of material similar to the Oolite of Ancaster, such as Newark and Grantham churches, have scarcely yielded to the effects of atmospheric influences." ("Old Lincolns.h.i.+re," vol. i., p. 23.) The well-known Colly-Weston slates are the lowest stratum of this rock. The fine old Roman "Newport Arch," which for some 700 years has "braved the battle and the breeze," a pretty good test of its durability, is built of this stone.

The base on which this lowest Oolite lies is the Northampton Sands, an irony stratum of red ferruginous sand and sandstone, the upper portion of it also being called the Lower Estuarine deposit. It is from this stratum so many springs arise in various parts of the county, as already mentioned, and among them the Woodhall well water. Its fresh water conditions show it to have been the bed of a great river, but a tidal river, as among the fossils which it contains some are marine sh.e.l.ls. In this formation is found the iron-stone, which is worked at Lincoln. Its commoner fossils are Lima duplicata, L. Dustonensis, Hinnites abjectus, Astarte elegans, Cardium Buckmani, Modiola Gibbosa, Ammonites Murchisoniae, Belemnites Acutus. Its ferruginous layers are (as given by Capt. Macdakin), {97a} Peroxide bed, clay ironstone, hard carbonate of iron, hard blue carbonate peroxidised band, blue ferruginous sand, ironstone nodules, bed of coprolites with iron pyrites.

And this brings us to the Lias formation, in which lies the lower part, amounting to rather more than a third, of the Woodhall wells. It is divided into the upper Lias of clay and shale; the middle Lias of Marlstone rock bed, clay, and ironstone; and the lower Lias of clays, ironstone clays, limestones. {97b} This formation, with a thickness of from 900 to 1,000 feet, runs across England from Yorks.h.i.+re and Lincolns.h.i.+re down to the coast of Dorset. The upper Lias of the Woodhall wells also helps to form the slope from 100 feet to 150 feet in thickness of the escarpment called "the Cliff," to the west of the Witham Fens, and to the north of Lincoln, by Fillingham, and so on. Lincoln itself stands on Lias beds, with a capping of the lower Oolite limestone. {97c} It contains many Belemnites, Lucina, Ammonites Bifrons, A. Serpentinus, A.

Communis, A. Heterophillus, Nucula Hammeri, Pleuromyae, {97d} and especially the Leda Ovum, which distinguishes it from other strata. The middle Lias, which underlies the upper, contains Ammonites Spinatus, A.

Margaritatus (in great abundance), Rhinconella, Icthyosauri, Plesiosauri, and fossil wood, etc. {98a} The lower Lias contains Ammonites Capricornus, with many pyrites, A. Ibex, A. Jamesoni, A. Armatus, A.

Oxynotus, A. Obtusus, A. Semicostatus, A. Bucklandi, A. Angulatus, A.

Planorbis, Grypha incurva very abundant, and fossils of many other kinds. {98b} This brings us to the base of the Woodhall Spa wells. For a full list of the fossils so far found at Woodhall, the reader is referred to Appendix II. at the and of this volume.

These strata are shewn in the diagram given at the head of this chapter.

In giving the history of the well in Chapter I., the writer did not state the properties of the Woodhall water; but as these depend upon the geological elements, from which it originates, this seems to be the proper place to state them. The official a.n.a.lysis made by Professor Frankland, F.R.S., 1875, is as follows:-{98c}

Parts Grains per gallon

Total solids in solution 2361.200 1652.8400

Organic carbon .362 .2604

Organic Nitrogen .532 .3724

Ammonia .810 .5070

Nitrogen as Nitrates and .009 .0063 Nitrites

Chlorine 1425.000 997.5000

Total combined nitrogen 1.208 .8456

Bromine 6.280 4.3960

Iodine .880 .6160

a.r.s.enicam .016 .0112

Temporary hardness 20.000 14.0000

Permanent do 245.000 171.5000

Total do. 265.000 185.5000

The water contains unusually large proportions of Iodine and Bromine.-E. Frankland.

The remarkable features of this a.n.a.lysis are the quant.i.ties of iodine and bromine. Professor Frankland, for the Geological Survey, found, of iodine, 6.1 grains in 10 gallons of the water; bromine, 44 grains in ditto.

As compared with the water of Cheltenham, of Leamington, and of the famed German Spa at Kreuznach, we have the original a.n.a.lysis of Mr. West, of Leeds, giving:-

In 10 galls. Iodine. Bromine.

Cheltenham one third grain one and two-thirds grains

Leamington one grain four grains

Kreuznach one and one-quarter grain twenty-five grains

Woodhall six and one-sixth grains forty-four grains

The Woodhall water, therefore, has five times the amount of iodine, and nearly twice the amount of bromine, of the strongest known Continental water. {99a}

I mentioned, in Chapter I., that the Dead Sea, in Palestine, was stronger in bromine than Woodhall. According to M. Marchand's a.n.a.lysis, it contains bromide of magnesium 74 times the amount at Kreuznach, or about 30 times the strength of Woodhall; but the other great ingredient of the Woodhall water, iodine, is absent from the Dead Sea. {99b} In iodine the only known water surpa.s.sing Woodhall Spa is the spring of Challes in Savoy, {99c} which contains 1.045 parts per 100,000 of water.

I may add that at Old Woodhall, about four miles distant from "The Spa,"

at a depth of 33 feet, in sinking a well, some 20 years ago, salt water was tapped, resembling in taste that of the Woodhall Spa well, but it gradually became less salt, and finally was replaced by a supply of fresh water. {99d}

There is one other geological feature of the neighbourhood of Woodhall, which has not yet been touched upon, viz., the Fens bordering on the Witham. These are said to have been, to some extent, drained by the Romans; {99e} but within the last few centuries they have been partially reclaimed, have relapsed into bog and mora.s.s, and been finally reclaimed for good, in quite recent times. The writer, when a boy, used to visit a large farmer, living in Blankney Fen, whose father built the house in which he resided. Before building, an artificial foundation had to be made, by transporting soil in boats, or carts, from _terra firma_ beyond the Fens, the whole Fen tract being more or less bog and swamp. When this had become sufficiently consolidated, the house and farm buildings were erected upon it; and from that centre roads were constructed, drains made, and the work of reclamation gradually extended. These drains, or "skirths," as they are sometimes called, were periodically cleaned by a "bab," a kind of dredge, with hooks at its under side to tear up plant roots. Great flocks of geese were kept, which were plucked alive several times a year, for the sale of the feathers, to make the famed Lincolns.h.i.+re feather beds, and quills for the pens, now rarely seen, although, 50 years ago, in universal use. Until the land had become systematically reclaimed, it still continued to be extensively flooded in the winter months, and all cattle had to be housed, or penned, during that time, on the artificially raised ground. It frequently happened that early frosts caught the farmer napping, with his cattle still afield; in which case they had to be driven home over the ice, and numbers were at times "screeved," _i.e._, "split up," in the process, and had to be slaughtered. The fen soil is a ma.s.s of decayed vegetation, chiefly moss, interlarded with silt, deposited by the sea, which formerly made its oozy way as far as Lincoln. Large trees of bog oak and other kinds are found in the soil. These, it is supposed, became rotted at their base by the acc.u.mulating peat; and the strong south-west winds, prevailing then as they do now, broke them off, and they are, in consequence, generally found with their heads lying in a north-easterly direction. Borings at different places show the fen soil to vary in depth from 24ft. at Boston to 14ft. at Martindale; but, as it has been gradually dried by drainage, it has considerably shrunk in thickness, and buried trees, which only a few years ago were beyond the reach of plough or spade, are now not uncommonly caught by the ploughshare.

The river Witham, which the visitor to Woodhall Spa sees skirting the railway, has pa.s.sed through more than one metamorphosis. Now confined by banks, which have been alternately renewed and broken down at different periods, before the drainage of the Fens, it spread over all that level tract of country, meandering by its many islands and through its oozy channels and meres, the resort of countless flocks of wild fowl and fish _ad infinitum_, but preserving still one main navigable artery, by which vessels of considerable tonnage could slowly sail to Lincoln. Acts were pa.s.sed, in the reigns of Edward the Third. Richard the Second, Henry the Seventh, Queen Elizabeth, and the two Charleses; and Commissioners were again and again appointed to effect the embanking and draining of these watery wastes, but with only temporary success; and it was not till 1787, or 1788, that the present complete system of drainage was commenced, which is now permanently established. {101a} And in these days, the Fens, once consisting as much of water as of land, at times even suffer from a scarcity of that commodity; drains, which within the writer's own recollection abounded with fish, being now often dry almost all the year round. At a much more remote period the Witham was probably a much stronger river, and largely conduced to altering the features of the county. This subject has been carefully investigated by our geologists, {101b} with the result that certain changes in the strata of the upper Witham valley, from its source near Grantham, and changes also in the lower valley of the Trent, go far to prove that the Trent, instead of, as it does now, flowing into the Humber, took a more easterly course, and joining forces with the Witham some miles above Lincoln, the united streams pushed their way through the gorge, or "break" in the cliff formation, which occurs there, and is technically known as "The Lincoln Gap," and continued their course to the sea by something like the present channel of the Witham. The idea of this "Lincoln Gap," though the term is not actually used, would seem to have originated with Mr. W. Bedford, who stated, in a paper already mentioned, read before "The Lincolns.h.i.+re Topographical Society," in 1841, that "the great breach below Lincoln could only be accounted for by the mighty force of agitated waters das.h.i.+ng against the rocks, through long ages". (Printed by W. and B.

Brookes, Lincoln, 1843, p. 24, &c.) The theory would seem to be now generally accepted. Thus: "that ancient river, the river" Witham, honoured, we believe, by the Druid as his sacred stream, {102} consecrated in a later age to the Christian, by the number of religious houses erected on its sh.o.r.es, through a yet earlier stage of its existence performed the laborious task of carving out the vale of Grantham, and so adding to the varied beauty of our county; then, by a kind of metempsychosis of the river spirit, it was absorbed in the body of the larger Trent; the two, like "John Anderson, my Joe," and his contented spouse, "climbed the hill together," to the Lincoln Gap, and hand in hand wended their seaward way, to help each other, perchance, in giving birth to the Fenland; or, according to another theory, in making its bed. Through a long era this union lasted; but, as the old saying is, "the course of true love never did run smooth"; a change geologic came over the scene, and, through force of circ.u.mstance, the two, so long wedded together, broke the connubial bond, and henceforth separated, pursuing each their different ways; the one, the Trent, the river of thirty fountains, betaking herself "to fresh woods and pastures new,"

after brief dalliance with the Ouse, became bosomed in the ample embrace of the Humber; the other, the humbler stream of the two, retaining its previous course, pursued the even tenor of its way through the flats of the Fenland, with their "cra.s.s air and rotten harrs," to find its consolation in the "dimpling smiles," but restless bosom, of the shallow "Boston Deeps." During the period of that ancient alliance of these two streams the tract of country between Lincoln and Boston, or rather between the points now occupied by those places, would be scoured by a greatly-augmented volume of water, and this may possibly account in some degree for the shallowness of "The Wash," and the number of submarine sandbanks which lie off the mouth of the present Witham. Had the union of the two streams continued to the present time, bringing down their united body of silt, Boston would either never have come into existence at all, or would have been much further from the sea than it is.

The precise period at which this riverine union prevailed would seem to be still an open question; and we may say, with Horace, _adhuc sub judice lis est_; for, whereas Professor Archibald Geikie, Director-General of the Government Geological Survey, {103a} gives his opinion that "the gravels which have been laid down by an older Trent, that flowed through the gorge in the Jura.s.sie escarpment at Lincoln, were later than the glacial deposits"; on the other hand, Mr. F. M. Burton, F.L.S., F.G.S., {103b} who has a thorough local knowledge of the county and its geological features, says there is sufficient evidence "to convince any reasonable mind that the present course of the Trent is not its original one; but that ages ago, in early pre-glacial times, I think, it pa.s.sed through the Lincoln Gap to the fenland beyond, which was then open bay."

We may well say with Pope: "Who shall decide when doctors disagree?"

{103c} This, however, is too large a subject for a chapter on the geology of Woodhall Spa; but this brief reference to it may serve to show the visitor, who has the taste and inclination for such pursuits, that there are still subjects for interesting investigation in our neighbourhood, on which he might well employ his capacities for research.