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 Hatfields 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 its 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
coals 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 worlds
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 1960s.
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 earths vegetation into huge rotting piles
that formed all the coal on earth today.
Finally...
Whichever way the coal was formed, theres
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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