Mexborough Times, August 16th, 1878
Visit of University Students Association to Conisborough
A paper read before the members of the University Students Association on their visit to Conisbrough, August 3, 1878 by Mr E.B.Jenkinson.
MAGNESIUM LIMESTONE STRATUM
The stratum which we stand is known by the name of magnesium limestone; so named because it is a combination of the carbonates of magnesium and lime; the proportions are about 54.3% of carbonate of lime, and 45.7% of carbonate of magnesia. It is often termed Dolominic limestone, after the French geologist, M.Dolomineu will stop.
You will observe that it is crystalline in its character. For building purposes it is most admirably adapted; more especially the stone octane from the same stratum Southwest of Worksop. The houses of Parliament on cheaply built of the same, quarried near Mansfield.
Conisbrough Castle was built only soon after the time of William the Conqueror, the chisel marks of the workmen yet visible, is a monument not only of the scale of the builders, but of their wisdom in the choice of material. I never pass the massive key without contrasty the “shoddy” work of the modern, with a splendidly tooled work of those masons of the olden time.
As you are all aware the magnesium Limestone forms a part of the Permian system, so called by Sir Roderick Murchison, from the ancient kingdom of Permia. The Permian strata lies immediately over the Carboniferous system, and are composed of five divisions; Red Marl, Upper Magnesium Limestone, Marls and Sandstone, lower magnesium limestone and the Red Marl and Grits
The schoolhouse at Warmsworth is built on the Middle Marl, and the Friends Meeting House in the same village on the Upper Limestone, the Upper Red Marl is to be found on the Eastern Edge of the limestone as it dips beneath the surface. Magnesium Limestone extends to Leeds in the North and Nottingham in the South, but as you near the southern boundary, it becomes more arenaceous or sandy in its character. The thickness of the full Permian series has been proved in various places, and at Warmsworth, where four of the divisions are found, it may be estimated at about 250 feet. To the question, what is lime, we answer as a chemist might answer. It is calcium combined with oxygen and carbonic acid. We stay a moment to enquire how was Limestone made; the first fact we must digest is that all limestone has been made under the surface of water, either fresh or salt.
The entire of the valley of the Don was a mass of swirling waters, which abraded the strata, carrying down the detritus to make newer strata, and so forming at one time the picturesque valley of the district, and the rich lowland pastures of the Vale of the Trent. Formerly it was a favourite theory to attribute the mountains and hills of our country to volcanic action; but further research proves that the mighty agent in these formations had been water aided largely by atmospheric influences. As Tennyson says:
“O earth, what changes has thou seen!
There were the long street roars, have been.
The stillness of the central sea.
The hills are shadows, and they flow.
From form to form, and nothing stand;
they melt like mist, the solid lands,
Like clouds they shape themselves and go.”
I am not aware of any evidence of glacial action having taken place where we now stand, and from the sinuous character of the River Don, I am led to think that by the action of its own water It has cut out its bed. The outer, or convex curves of the river, from the force of the water would gradually extend outward, the cliff being worn away; whilst the concave or inner curves would have deposited near them the alluvium brought down.
You have a good example between Conisbrough and Sprotborough, the River near the old lime kilns having cut its way quite close to the limestone on the southside, whilst on the North there is a tolerably broad deposit of alluvium. A little beyond the Cliff Bridge the reverse you see, the alluvia being deposited on the south side.
Before I speak further of the limestone strata you will note this that the coal measures under our feet of complete. Every known bed of coal in the Yorkshire field lies beneath is. As you will see in the vertical plan which I have prepared, there are 15 seams of coal of two feet and upwards, including the famous Barnsley and Silkstone coal seams. Much fear has been expressed by Sir William Armstrong, Prof Jeavons and others that our coal fields will be speedily exhausted, and as a result, our nation becomes once again agricultural and Pastoral. At the instance of the House of Commons a Commission sat in 1871, and from the blue books in my possession. I find that Prof Ramsay states that there are 900 square miles of coal to the east of the margin of the magnesium limestone at Conisbrough, and that the total quantity of coal available under this area at a depth not exceeding 4000 feet, which is a workable depth, is 23,082 millions of tons.
The future Coal fields of Yorkshire and Lincolnshire, when the town Barnsley has become efiete through the exhaustion of the minerals in its neighbourhood, will be bounded on the West by the escarpment limestone and will probably extend as far east as the banks of the silvery Trent.
I will now speak of a characteristic of the limestone strata generally which has been brought more particularly under my notice by the fortunate discovery by myself of the remains of extinct animals.
I refer to the existence of crevasses and caves which are very common in these rocks. How have these been made? The limestone as you can see is full of joints or divisional planes, and the water circulating through the strata, carrying with it, sand and stones, would, in time, by a mechanical process, cutout hollows in the limestone; but, this is not the only way, or by any means, the principal way in which the work has been done. The limestone as I have told you, is largely composed of carbonate of lime, which though insoluble in ordIinary water, is readily dissolved by any liquid containing carbonic acid. The acid is present in considerable quantities in rainwater, and is increased by organic bodies with which it comes in contact as it passes along. By this agent mainly have the caves which are so rich in fossil remains been excavated. The pieces of stalagmite by which you may find in the cutting near you, are proof of what I say.
The fossil bones were found about 20 feet below the surface, and though I was not present when they were dugout, I judge from careful examination of the cutting that it was not their original resting place. There was no cave there as far as as I could learn, and the bones were found embedded in clay containing detached pieces of limestone, which had apparently rolled down the slope and fallen into the crevasse.
The bones form a most interesting collection proving as they do the existence of at least four distinct species of mammals. The mammoth (Elephas Primigenius) rhinoceros (Tichocinus) Hyena (Spelieu) and Horse. That the remains originally had a place in a cave. Those who will study the habits of the hyena will at once conclude. This species of the order Carnivora takes its prey into caves for the purpose of devouring it, and after careful examination of the specimen (femur of rhinoceros) you will see most distinctly the teeth marks of the hyena.
The specimen of the rhinoceros and mammoth, both of which were woolly or hairy, indicate that a great climatic change has taken place in our country. Nature adapts itself to circumstances, and the intense cold of that epoch undoubtedly materially modified not only the habits but the physique of the animals.
Proffessor Ramsay gives it as his opinion, that the Indian Elephant is a mere variety of the Mammoth. The first Mammoth must have crossed over from the old continent of Europe when England was connected with the mainland; and after the severance took place, “crimped, convened and confined” within small as area the species gradually dwindled down and out and ultimately died off.
As no remains of man were found with these bones and from their discovery in the lower limestone, I have regarded them as of early Plienstocene age, but that opinion was to be taken lightly as bones of the same species have been discovered in Robin Hood’s cave, Creswell crags, accompanied by Flint and other implements clearly proving the existence of man.
I thank you for your attention to these crude remarks; let me urge you to prosecute your studies persistently.
Nature is a shy goddess, she must be ruled with unwearied assiduously before she will yield her charms; ardency of love is lost unless accompanied by unwearied efforts.