Hatfield Colliery
Climate & Coal

The changing climate of Stainforth leading to the formation of present day coal deposits.

Backwards in time.
If time travel was possible and we could travel backwards 300 million years, we could then follow the series of climatic changes which shaped the earth beneath our feet. Standing in this same place we would witness the changes between swamps, jungles, deserts and sea beds which led to the formation of the extensive coal deposits that exist today, and which have played such an important part in the shape of Stainforth over the last hundred years.

Changing landscapes.
How do we know that such changes occurred in the climate, affecting the land and all that lived on it?
To reach the layers of coal which are mined at Hatfield Colliery, the company which sank the shafts had to dig down through many layers of different types of rock. These layers form a map which show us how the landscape changed, in some cases being flat and sandy, and in others being rolling hills, covered in tropical jungle. If you read the page about the history of Hatfield Colliery, you will see that there were problems encountered by the engineers when they passed through a layer of red sandstone. This was a porous layer of sedimentary rock, through which the natural water table found access into the newly opened shafts. Below the red sandstone layer were yet more layers of rock, some soft and friable, others hard and dense. Although most layers are devoid of anything of note, save hard iron nodules, deposited there by years of seeping water, some contain fossils of sea creatures, such as bivalve molluscs, showing that this area was once submerged beneath a sea or lake. Others contain fossils of plants, such as the prehistoric tree, found in the area near the bottom of Hatfield’s No.2 shaft. Although I never heard of animal or dinosaur fossils being found at Hatfield, I have heard of such finds at other coal mines.

When coal is examined closely you can see that it is made up of tiny fragments of petrified plants. The plants were once part of a swamp which existed for many thousands of years. Throughout the existence of the swamp, plants grew and plants died, the dead matter falling to the floor to form a layer like an organic carpet. As more dead matter fell, the bottom of this "carpet" became compressed by the weight above. At times the land would be subject to floods and cataclysmic catastrophes. The carpets of compressed vegetation, or "peat", as it is more commonly known, became buried under layers of silt or sand, which in turn became compressed as more matter built up above these new layers. The layers above would compress the layers below, which in turn were affected by the pressure and the heat of the earth. The peat underwent subtle changes over a long period of time, changing first to "soft brown coal", and eventually to harder types of coal, until some became "anthracite", the hardest coal of all. This process would have taken an extremely long time. Some leading scientists have suggested that a single layer of peat, less than a centimetre thick, could have taken several thousand years to have been formed. When the peat is compressed to form coal, a centimetre of peat would be crushed to only a couple of millimetres thick. Others have stated that the process may have been much quicker, but still involved the passage of a great deal of time. (See "Sedimentation Vs Creation" at the bottom of this page for another view)

Qualities of coal.
Compression not only affects the density of coal, it also affects the carbon content, a means by which coal is classified. The main types are soft brown coal or lignite, which contains around 50% carbon, bituminous coal, which is a mixture of shiny and dull coal and which contains around 75% carbon, and anthracite, which is hard and shiny and contains around 90% carbon.

There are many different seams of coal below Stainforth, some as thick as two metres or more. When one looks at a coal seam, you can see it is formed from many slightly different coloured bands, or layers, some only millimetres in thickness. Since each fraction of the seam took so long to form, one can see that it would have taken an incredibly long time to form a seam of coal as thick as the Barnsley seam, which is almost three metres thick in some places. In one area of Hatfield Colliery the Barnsley seam is separated from the lower Dunsil seam by a narrow band of dirt, just a couple of centimetres thick. This gives a total "section" of almost four metres, which would have taken hundreds of thousands of years to form, and then around three hundred million years for the layers of rock and other seams of coal to have formed above these two seams.

Stored Energy.
When plants are alive they soak up the sunlight, which is stored as energy. Even though the plants have died and have been compressed for millions of years, it is this energy which give coal it’s great value today. Different seams form in different conditions, which why coal from the Barnsley seam has different qualities to coal from another seam, such as the High Hazel. These qualities can either add or detract from the coal’s usefulness. For instance, many of the deeper coal seams are also high in unwanted sulphur, and many of the shallower seams, which may have a lower sulphur content, can be found to contain a high level of impurities, or ash. There are nineteen seams of coal with a recognised useful potential at Hatfield, though in reality only four of these seams have been mined for profit. These are the High Hazel, with an average seam thickness of 140cm at a depth of 634m, the Kents Thick, (mined on a very limited basis) with an average seam thickness of 80cm at a depth of 665m, the Barnsley, with an average thickness of 280cm at a depth of 703m, and the Dunsil, with an average seam thickness of 70cm at a depth of 720m.

So, if each seam of coal took several thousand years to form, we would have to stand in swamp, jungle, desert and sea to watch the changes of this patch of land we call Stainforth, and this for each and every seam which lay below us.

Man and mineral.
The relationship between man and coal can be traced back through thousands of years. It is probable that the first coal used by man had been found laying on the surface, the result of glacial action during the last ice age. The glaciers which had rumbled inexorably across the Stainforth landscape and that of the surrounding continent, retreated to the north, where they would cling on tentatively for several thousand years while the southern climate warmed once again. The passing of the glaciers left their own distinct marks, with vast areas of bedrock and low laying strata being ground into what we know today as glacial deposits. If you dig more than a few feet down almost anywhere in Stainforth you will find yourself digging through a layer of sand and gravel, the pebbles worn round and smooth after their rendezvous with an ice age glacier.
As well as leaving behind trails of rocks and gravel, outcrops of shallow coal seams were exposed, especially near the coast, where in some cases coal would wash ashore from outcrops laying beneath the waves. Nobody knows precisely how post ice-age man discovered the heat rendering qualities of this black mineral, but coal has been used by people throughout the world since this time.
It was not until the Industrial Revolution that the use of coal became so important. The advent of the steam engine and the power it provided to drive the gears of industry produced a need for coal the world over. The first steam engines were actually used as pumps for removing water from the coal mines themselves. In a relatively short time they were being used to haul coal and other commodities across a shrinking continent.

Between 1700 and 1900, Great Britain was the world’s largest coal producing nation.

Hatfield Colliery is situated by the side of a busy railway, which in the early days of the mine was used to carry the produce of the colliery to Thorpe Marsh power station, some three mile distant. There are probably many Stainforth residents who, like myself, remember the hissing and roaring steam engines, as they passed beneath the railway bridge with their long trains of coal wagons.

It was this connection with the power industry that blackened the name of coal from the time following the 1960’s. It was discovered that coal fired power stations were directly responsible for the destruction of miles of forest land and the poisoning of lakes in northern Europe. The cause was the sulphur being released from the coal when it was burned, and which, through the use of tall chimney stacks, was distributed into the higher atmosphere, where it drifted across the northern part of the continent, before falling back to earth as acid rain.

Nowadays there are stringent regulations regarding the burning of fossil fuels, which has led to "cleaner electricity" producing power plants. There are still many horror stories to be found though, particularly from the United States, Russia and the Far East, where such legislation has been slow to come into force, and where coal fired power plants still present serious health risks to those who live nearby.

Sedimentation Vs Creation
In America (where else?) there is a theory held by a group of devoutly religious people calling themselves "Creationists", regarding the formation of coal deposits. They believe that the world and everything on it was created by God in seven days. Now these are very intelligent people, with a high standard of university education, so they have thought long and hard about how to explain the formation of coal seams, as well as such abominations as dinosaur fossils. It is their belief that coal was formed during the great flood for which Noah built his ark. There are many Creationists web sites where they go to great lengths to explain how Noah refused to let the dinosaurs on his ark, and how the following deluge washed all of the earth’s vegetation into huge rotting piles that formed all the coal on earth today.

Finally...
Whichever way the coal was formed, there’s no denying the impact this fossil fuel has had on the history of Stainforth. Now we place our trust in the new owners of Hatfield Colliery that the future of Stainforth will remain linked with coal, and will be a clean and healthy future for us all.

 

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