Nathaniel John Winch

“ The beds of shale or plate (as it is called) are very numerous, and are found alternating with the rocks of limestone and sandstone. They are seldom so thick as 7 or 8 fathoms; but the plate sill, which is the lowest bed in the section below that of Dufton, measures 10 fathoms. Shale alternating with sandstone in thin layers sometimes forms beds of considerable thickness, (see section of Hely field,) which are called grey beds: when containing laminæ of hardstone and iron pyrites it is called a girdle bed. Iron pyrites is found imbedded in the shales in great abundance, and in various forms ”

“ In the mountainous parts of the district the seams are extremely limited in extent, being soon squeezed out, as the miners term it, and seldom exceeding 20 inches in thickness. In the high grounds, near the sources of the South Tyne and the Allen, Coarse or Grow coal abounds; and on Aldstone moor five seams of this fossil are imbedded between the grindstone sill and the Tyne bottom limestone: it does not appear among the sills on the Derwent towards the Cast, or of Dufton towards the west of Aldstone, but occurs near the summit of Cross Fell, where no other is to be met with. ”

“ When the veins in Weardale point east and west, they hade towards the south; but in Allendale and in the Aldstone moor country they generally hade towards the north: the strata are universally elevated on the side towards which the veins dip.
Veins, that are otherwise favourably circumstanced for producing ore, are more particularly so if the throw or alteration in the level of the beds of limestone, occasioned by the vein, does not exceed 1 or 2 fathoms; for then both cheeks of the vein correspond in their nature, and limestone does not become opposed to shale or other barren stratum. ”

“ A perpendicular fissure, the sides of which are quite smooth, divides the stony contents of the dyke into two equal parts, and when perforated was found to be filled with soft clay and water. On the south side the coal-measures preserve their usual dip of 5° until close to the dyke: on the northern from the distance of 150 yards they rise to the dyke at an angle of 20°, but at the distance of 600 yards they regain their accustomed position. In some parts the coal is deteriorated in quality to the distance of 20 yards from the dyke ”

“ Hornblende rock is by no means uncommon among these hills Housy crag, which rises above the farm house near Langley ford, in the valley between Hedgehope and Cheviot, is composed of a coarse grained variety of this rock, closely allied to the porphyry, and the perpendicular cliffs of Hellhole on the opposite side of the Cheviot consist also of the same rock.
The only metallic ores known to exist in this district are, bog iron-ore, which is found in the bottoms of morasses, and red ochre with nodules of hematite from a small vein traversing the rocks above Langley-ford. ”

“ It is well ascertained that the magnesian limestone of this district, as is the case with that of Derbyshire and Yorkshire, rests upon the coal-measures. No coal mine however has yet been won in Northumberland or Durham, by sinking a shaft through the limestone, although the workings of some collieries situated on its western boundary have been carried underneath it. It is therefore a matter of great importance to those who have royalties within its limits to know under what thickness of limestone the coal measures are buried ”

“ Crow coal generally rests upon a thil or plate of slate-clay; but the beds being very uncertain in their extent are seldom noticed in the Lead-mine sections. They are worked at a small expense by means of drifts into the sides of the hills, and as fuel is scarce in the mountainous district, Crow coal becomes an object worthy of attention. ”

“ The average dip of the coal measures is 1 inch in 20; but this inclination is by no means uniform in every part of the district. Thus that seam of coal called the High Main which lies buried at Jarrow, under 160 fathoms of beds of stone, soon rises to the clay in a north-easterly direction, and bassets out in the cliffs between Cullercoats and Tynemouth. In its north-westerly range it reaches Benwell hills, and at Pontop nearly 18 miles due west of the sea shore at Sunderland it is met with at 38 fathoms from the surface. ”

“ The coal-seams and the rocky strata which together constitute the coal-formation of Newcastle and Sunderland, are in part covered by the magnesian limestone, and rest upon the lead-mine measures. They occupy a hollow, or trough, of which the extreme length from the Alklington colliery, near the Coquet, in the north, to Cockfield, in the neighbourhood of West-Auckland, is 58 miles; and the breadth, from Bywill on the Tyne, to the sea-shore, is 24 miles. ”

“ Where the dyke reaches the surface a quarry of the basalt was formerly worked, which has lately been cleared. A small seam of coal meets the basalt at no great depth from the quarry-head, but the place of contact is at present inaccessible. In the neighbouring colliery both portions of the vein hold their course through the seam there worked, and the coal is charred by their influence. ”

“ Galena has been found in a dyke in Willington colliery, and a small string of the same ore has been observed in the main dyke at Whitley. A salt spring issues from a slip in Birtley colliery.
The dykes are an endless source of difficulty and expense to the coal owner, throwing the seams out of their levels, and filling the mines with water and fire damp. At the same time they are not without their use; when veins are filled, as is often the case, with stiff clay, numerous springs are damned up and brought to the surface ”

“ The specimens are generally intersected by veins of iron pyrites and slate-clay. Some buildings stand upon the bank out of which this mineral was quarried, and the proprietor to save them from being undermined has built a wall close to the face of the rock; so that satin-spar is no longer to be procured, and is become a scarce mineral.
There are few parts of the Lead-mine district in which coal is not to be found, though the seams cannot be compared in magnitude to those of the Newcastle formation. ”

“ Masses of blue coralloid limestone, the produce of the lead-mine district, are found at the surface at Cullercoats above the magnesian limestone. Similar blocks are found dispersed over the other formations.
Masses of close-grained sandstone occur every where in like manner.
Masses of hard black basalt are found every where in abundance. From this stone the ancient inhabitants of Britain formed the heads of their battle-axes, which the people call Celts. They resemble in shape the tomahawks brought from the South Sea islands. ”

“ The Thistle pit dyke which is a downcast of eight fathoms to the south, and traverses the Coal-field from west to east, appears to have been as well known to the miners who lived nearly a century since, as to those of the present day. ”

“ Fissures that divide the strata, but do not alter their level, and which sometimes do not descend lower than the upper seams of coal. These are called gashes by Williams, and washes by our miners: they are filled with water, clay, sand, and rounded sandstone pebbles similar to those in the beds of rivulets.
3. Basin-formed depressions in the floors of the mines, called swellies by the miners; by which the coal is considerably thickened, the roof of the seam preserving its regularity. These occur when the coal is nearly horizontal. ”

“ Anthony's, and at an adjoining colliery, the Low Main coal is found at 59 fathoms below the High Main; but though the seam proved to be 61⁄2 feet thick, the workings of it were abandoned as unprofitable; the coal being extremely fragile, and the mines very subject to the fire damp. On the south side of the Tyne, at Felling, Tyne Main, and Gateshead Fell, the quality of this coal is very much improved, and under the name of the Hutton Main, it forms one of the most valuable seams on the Wear. ”

“ The most valuable seam in the whole Coalfield in point of thickness and quality is that called the High Main, of the mines situated between Newcastle and Shields. It there averages above 6 feet from the roof to the floor, contains a large proportion of bitumen, and is sufficiently hard to bear carriage without breaking into very small fragments. ”

“ The northern and southern basaltic portions of the vein, the one 5 the other 6 feet in thickness, are there 13 feet apart, and are separated from one another by a confused heap of fragments of sandstone and shale broken from the coal-measures. With these fragments are found balls of basaltic tufa parting into concentric layers, and of a light yellowish brown colour: the balls are most abundant on the sides of the rubble near to the basalt. ”

“ Along the coast of Durham from Shields to Hartlepool the limestone strata dip to the south-east. At Chapted main near South Shields, the coal measures, although approaching the limestone, rise towards the sea, in conformity to their direction on the north side of the Tyne; but at Painshaw, New bottle, Rainton, &c. they dip to the south-east, the limestone being there protruded into the Coal-field beyond the prolongation of that line, from which the coal measures that are without covering begin to rise in an eastern direction. ”

“ Splint coal is also found at Throckley, Kenton, and some of the Lambton collieries situated on the Wear. Coarse coal occurs at Cockfield and many other places. These two varieties, containing little bitumen and less sulphur, are used in iron foundries, potteries, &c.; and splint serves as a material for building cottages and outhouses in the neighbourhood of Throckley Fell.
Potter's clay is found immediately below the vegetable soil. Its colour is blueish or smoke grey, and sometimes yellow approaching to orange, in consequence of a mixture of iron ochre. ”

“ Botryoidal masses of fetid limestone devoid of magnesia, in balls varying from the size of a pea to two feet in diameter, imbedded in soft, marly, magnesian limestone, are found at Hartlepool, in the quarry at Building hill, near Sunderland, and on the sea-coast a mile or two north of Monk Wearmouth. These balls are radiated from the center, their colour hair brown, fracture shining, cross fracture splendent approaching to vitreous: white calcareous spar is frequently observed within them. ”

“ It rests upon the lead-mine sills, and shoots on the banks of the Tees into regular columns of considerable magnitude and elevation. A few miles below this cascade, and about three above Middleton, perpendicular basaltic rocks again form the banks of the river. To these, iron chains have been fastened for supporting Winch bridge. This remarkable structure (if it can be so called) is a plank 2 feet in breath with low hand rails, suspended 56 feet above the Tees, which is here 63 feet wide. Some miners contrived it for the purpose of passing from the county of Durham to Holwick in Yorkshire. ”

“ In this part of the mining field considerable uniformity may be observed amongst the sills. Thus the sections at Allenheads, Coal cleugh, Aldstone moor, and in Weardale, are allied to those above Blanchland on the Derwent, and agree very closely with one another: if therefore those of Hely field, Aldstone moor, Dufton Fell, and its sequel, be taken in succession, they will give no very inaccurate representation of the prevailing series of beds in this part of the district, and the total thickness of these beds thus obtained will be 2717 feet. ”

“ It appears therefore that their dip is not affected by the limestone. It is a circumstance however too well ascertained to admit of a doubt, though difficult to be accounted for, that the coal is deteriorated in quality where covered by the limestone.
Galena is the only metallic ore that I have observed in this limestone. It has been found in small strings at Whitby quarry, Clacks-heugh Blackhall-rocks, Ryehope, and amongst the rocks below Tynemouth castle: at the latter place calcareous spar is the matrix. ”

“ It crops out on Byker Hill, Whickham Banks, and Gateshead Fell, where it is about 11 fathoms thick. It is quarried for the well known Newcastle grindstones, and from its softer parts filtering stones are made. In many places the upper part of this bed is abundantly impregnated with yellow ochre, which is sold under the name of die-sand.
Fire-stone resembles the grindstone in colour and fracture, but is soft when first worked. The best is quarried at Burradon near Killingworth: glass-house furnaces are constructed with it.
White post is a fine-grained sandstone, tolerably hard. ”

“ It is useless therefore to attempt any general section of the Coal formation; and it will be seen in the sections subjoined to this paper, how difficult it is from want of uniformity in the beds to identify the coal seams in the vicinity of Newcastle. I refer to the sections of Hebburn and of Sheriff hill, as exhibiting when taken in succession, a series of Coal measures of the thickness of about 270 fathoms. In the former colliery are the beds which lie above the High Main coal ”