Geography - Coal mining in the Goitzsche/ The geology of the Goitzsche

Members of the project
Andreas Bunge
Anja Köppe
René Hilbig
Janine Körner

1. 
Introduction
The historical development of the Goitzsche

The open-cast mine “Goitzsche” is situated in Saxony-Anhalt and Saxony, in the area between Bitterfeld and Delitzsch. Its total area amounts to 62 km2  two thirds of which are in Saxony-Anhalt, and one third in Saxony. Coming from Bitterfeld (in the direction of Wittenberg) you can reach it following the B 100. The adjoining villages and towns include Bitterfeld, Muldenstein, Friedersdorf, Muehlbeck, Pouch, Loebnitz, Sausedlitz, Laue, Petersroda and Holzweißig.
In 1949 the development of the open-cast mine ”Goitzsche” started south-east of Bitterfeld. Within the 40 years of mining 317 million tons of brown coal were extracted. To do so about 850 million tons of overburden had to be moved.
In 1955 amber was discovered in the Bitterfeld mine. But mining only started in 1975 after the geological analysis. Until 1990 about 408 tons of precious minerals were extracted. After that the extraction was stopped because of financial reasons. Moor oaks of an age between 4000 and 6000 years were found, too. 
After stopping coal-mining in 1991 the redevelopment of the area of 60 km_ began in order to create an urban recreation area. After flooding this area will form a lake district with about 400 million m2 of water, 25 km2 water area and a shore line of 66 km.
In 1997 the construction of the flooding equipment for the former open-cast mine “Goitzsche” began. It consists of  the dikes, the connecting pipelines and the actual flooding canal in Muehlbeck. All this serves to conduct water from the “Mulde River” to the former mining area. After the completion of this equipment the test flooding started on 6th July 1999. At that time 1 m3 of water per second was flowing into the former mining area.
On 7th  May 1999 the “real” flooding began. Since then about 3 m3 per second (depending on the water level of the Mulde River) are conducted into the former mining area of Muehlbeck and from there on to the former mining area of Niemegk to fill it with “nice” water of the Mulde River.
On 6th June 1999 the building of the sea-level tower “Pegelturm” started directly at the flooding canal. The upper part of the “Pegelturm”was placed on its base on 16th March 2000. You can reach the tower via a swimming 220-metre-long pontoon bridge, which will rise its level in the process of flooding.
On 13th April 2000 the lakeside promenade on the edge of the “Goitzsche” was opened to the public. The way leading from the outskirts of Bitterfeld to the “Pegelturm” is even illuminated at night.
On 28th July 2000 the flooding of the former mining area Roesa was begun with the help of  a pipeline and a pumping station.


2. Development of coal-mining in the Bitterfeld area until 1900
  • 1804

  • The first attempt to mine the coal of Bitterfeld. It failed because the ground-water level couldn`t be kept under control. 
  • 1834

  • development of the Royal Mine at the “Farm House”
  • 1838

  • beginning of test excavations
  • 1839

  • opening up of the mine “Auguste”
  • 1842

  • mine “Wilhelm” in Hohenlubast mentioned for the first time
  • 1842

  • foundation of mine “Richard” in Sandersdorf
  • 1843

  • opening up this mine
  • 1844

  • abandonment of the Royal Mine at the “Farm House”
  • 1845

  • development of the mine “Moehring”
  • 1845

  • development of the mine “Johannes” (No 6) near Wolfen
  • 1846

  • opening up of this mine
  • 1846

  • development of  mine No 9 near Grossmoehlau
  • 1847

  • foundation of the “German Mine” near Zscherndorf
  • 1848

  • opening up of  the  mine “Adelheid”
  • 1850

  • mine No 79 comes into operation near Greppin
  • 1852

  • foundation of mine “vergissmeinicht” (No 291) near Zscherndorf
  • 1855

  • development of the mine “Maria-Theresia”
  • 1856

  • foundation of the mine “Ausdauer”
  • 1858

  • foundation of the mine “Gemeinsinn” in Delitzsch
  • 1859

  • the most important mines in the Bitterfeld area 

    name                                            extracted coal                        workers

    mines No 64,222,297                    419,197 t  (all in all)               95 (all in all)
    mine “Johannes”                           269,975 t                               50
    mine “Richard”                             137,554 t                               39
    mine “Auguste”                            141,729 t                                41

    In the Bitterfeld mines locomotives were used for excavation. Railroad wagons were pushed near the open-cast mine and then pulled by horses up to the real working place. In 1849  steam engines were introduced in the “German Mine”. In 1857 the brown coal-mines were connected to the railway network. 
    In the two years of crisis 1858 and 1859 the output per worker sank. 

    1857: 356.8 t
    1860: 346.8 t
    1861: 494.1 t

    Some mines were closed because of free competition since they were not profitable due to their unfavourable position e.g. in the vast forest areas of the Duebener Heath.

    In 1864 the amount of coal was increased as the table shows:
    (diagram amounting of raw coal 1864)

    Name                                                    Amount of coal in tons

    “German Mine”                                     492,230
    mine “Auguste”                                      467,587
    mine No 79 (near Greppin)                     409,880
    mine No 314 (near Muldenstein)            275,999
    mine “Johannes”                                     234,301
    mine “Ausdauer”                                    127,074
    mine “Richard”                                       123,778
    mine “Vergissmeinicht”                          109,501

    In Bitterfeld the following property situations had formed:

    Private Mines 

    1. mine “Auguste”
    2. mine “Richard”
    3. “German Mine”
    4. mine “Vergissmeinicht”
    5. mine „Lutherslinde“

    Mines owned by banks 

    1. mine “Johannes”
    2. mine “Maria-Theresia”

    Mines dominated by industrial capital

    1. mine “Ausdauer”

    Communal Mines 

    1.  mine “Gemeinsinn”
    2. mine  „Maria Theresia“

    Thus banks and industrial capital brought 30 % of the coal- mines under their control.
    At that time more workers were employed. Hence a miner`s capacity increased like this:

    1843                                      273 t                                            100% 
    1860                                      346 t                                            126 % 
    1870                                      518 t                                            189 %

    A daily shift lasted 16 hours. In 1840 a worker earned 25 “Silbergroschen” (silver coins) per “Kubik-Lachter” of raw coal. A shaft worker earned two, a pit foreman three Talers.
    In 1869 there were eight brown coal-mining companies with 660 workers. There was an output of 6,900 447 Zentner of raw brown coal (1 Zentner = 50 kg) worth 209,505 Taler.
    6,380 628 Zentner worth 195,674 Taler were sold. The average value per Zentner amounted to 0,92 Silbergroschen per Zentner. Thus one worker produced 10,455 Zentner. Besides 16 steam engines (323 PS) were used.
    In 18 74 ten brown coal factories employing 1,189 workers existed. There was an output of 13,687 381 Zentner of raw brown coal worth 521,551 Taler. 13,687 045 Zentner were sold for a price of 502,963 Taler. The average value per Zentner amounted to 1,14 Silbergroschen per Zentner. Thus one worker produced 11,512 Zentner. Factories used 23 steam engines (421 PS). 

    Property situation at the end of these years:

    Communal Mines 

    mine “Maria Theresia”

    Private Mines

    1. mine “Auguste”
    2. mine “Richard”
    3. “German Mine”
    4. mine “Vergissmeinicht”
    5. mine “Marie”
    6. mine “Hermine”

    Mines owned by banks and industries

    1. mine “Antonie”
    2. mine “ Luise” Corp.
    3. mine “ Ausdauer” Corp.
    4. mine “Gemeinsinn” Corp.
    5. “Greppin Factories Corporation”
     

    Then a crisis which set in in 1873 began to show its effects on the output per person.

    Year/output per person(diagramm output per person)

    1872/516,6 t
    1873/ 642,4 t
    1874/593,0 t
    1875/560,2 t
    1876/529,9 t
    1877/628,2 t
    1878/677,6 t

    The production of brown coal briquettes started at the end of the 1870s, at the beginning of the 1880s. This led to an upswing of the briquette industry. The extraordinary competitions caused a decrease of the coal prices between 1879 and 1884 from 13.7 down to 12.5 Pfennigs per hl. Because of the production of briquettes the district of bitterfeld could become more competitive. This positive trend again led to the following new establishments:
     

  • 1888

  • development ot the mine “Friedrich 3rd”
  • 1888

  • development of the mine “Golpa”
  • 1891

  • opening up of the brown coal company in Petersroda
  • 1897

  • foundation of the mine “Erich” in Sandersdorf
  • 1898 
  • 1899

  • development of the mine “Karl Friedrich 2nd”
  • 1895

  • the mine “Marie” (a new open-cast mine), because mine “Klara X” had to be closed temporarily because of flooding

    Property situation at the end of  1900

    At the end of  the 19th century banks already own 50% of the mines.

    Private Mines

    1. mine “Auguste”
    2. mine “Richard”
    3. “German Mine”
    4. mine “Vergissmeinicht”
    5. mine „Marie“
    6. mine „Ferdinand 3rd“
    7. mine „Antonie“

    Mines controlled by banks and industries

    1. mine “Luise” inc.
    2. mine « Ausdauer » inc.
    3. mine „Erich“
    4. mine „ferdinand 1st/2nd“
    5. „Greppin Mines“ corp.
    6. mine „Hermine“

    By the introduction of machines (excavators) the output of a miner rose up as follows:
     

    1870 518 t 100%
    1880 580 t 112%
    1890 554 t 107%
    1900 1010 t 194%

    On 14th April in 1883 the first monopoly union was formed in Bitterfeld. This union of the mines “Luise”, “Richard”, “Hermine” and the “German Mine” was called “Union of Bitterfeld Industrials”. In the course of 20 years the exploitation of one worker increased by 50 per cent. In 1863 a worker produced 436 t, and in 1885 - 655 t of coal.
     
    Amount of raw coal 1889 1895 1899
     Mine "Deutsche Grube" 253.869 t 304.638 t 388.845 t
    Mine Luise 229.928 t 329.364 t 398.066 t
    Mine Auguste 187.154 t 211.657 t 279.927 t
    Mine Hermine 197.717 t 173.462 t 261.734 t
    Mine No 6 (near by Wolfen) 132.434 t 155.203 t 220.440 t
    Mine Antonie 127.080 t 137.018 t 137.343 t
    Mine Marie  99.771 t  * 158.417 t
     

3. The history of the Goitzsche
  • 1830

  • infertile land planted with pine trees
  • 1908

  • pening up of the mines ”Leopold” and “Theodor”
  • 1908-1961

  • open-cast mine Holzweissig uses electric railway engines
  • 1911

  • the Siemens-Schuckert-Company receives the license to search for coal in the “Goitzsche”
  • 1915

  • mechanisation of open-cast mining with the help of an electric spoon excavator
  • 1917

  • first attempts with mechanical movement of the overlay shelf
  • 1921-1928

  • open-cast mine Paupitzsch/Petersroda
  • 1929

  • Bitterfeld bought the front part of the “Goitzsche”
  • 1947

  • first plans for opening the “Goitzsche”
  • 1949

  • opening of the “Goitzsche”
  • 1951

  • open-cast mining in the “Goitzsche”
    opening up of the open-cast mine in Muldenstein
  • 1951-1991

  • the “Goitzsche” opened up by a spoon excavator
  • April 1953

  • courses of Rivers Leine and Lober shifted to prevent flooding the mining areas
  • 1953-1955

  • the railway route  Bitterfeld-Berlin was rebuilt north
  • 1956

  • destruction of the village Zoeckeritz
  • 1956-1961

  • railway route Leipzig-Berlin and the B 184 rebuilt west
  • 50s

  • recultivation of slagheaps
  • 1961

  • beginning of regular reforestation mostly with poplars and oak-trees
  • 1961

  • opening up of the open-cast mine Holzweissig-west
  • 1966-1975

  • transfer of the Mulde River bed by 9.2 km
  • 1972

  • closing down the open-cast Muldenstein
  • 1976

  • flooding that cast
  • 1976

  • creation of the Muldewater Reservoir
  • 1976

  • the village “Paupitzsch” destroyed
  • 1978

  • village Niemegk destroyed
  • 1980

  • closing down the open-cast mine Holzweissig-West
  • Sept. 1984-June 1985

  • longest transfer of huge mining equipment from open-cast mine of Leipzig to the Goitzsche
  • 1984

  • courses of Rivers Lober and Leine changed once again
  • 1984-1991

  • open-cast mine Roesa
  • 1989

  • temporary establishment of three nature reserves
  • 1990

  • forest area opened for relaxation
  • 1990

  • another change of River Mulde and destruction of five villages prevented, although mining had been planned up to 2040
  • 15th May 1991

  • redevelopment, flattening, stabilization of slopes, recultivation and removement of mining equipment started
  • 1998

  • beginning of  flooding - “Bitterfeld Sea”

4. The geology of the Goitzsche
The earth layers of the Goitzche

The earth layer  profile of the Goitzsche consists of main- and countless smaller layers.
The origin time as well as the substances which the smaller layers consist of is not precisely to be determined.So we confine ourselves to the most imporant six layer sorts and want to explain in simple but in geologically correct ways.The most frequent layer,which the geologists also call terrace gravel,consists mainly of gravel sand.It came into being in the Pleistocene period 125.000-6000.000 years ago.This geological period is devided again into different periods whereas 
the development  of gravel sand belongs to both the Elster cold spell and to the Saale cold spell.The thickness of this layer can amount up to 8 metres.
The second layer,which has to be considered,has also came into being in the Pleistocene period and is called clay ("B‰nderton").This clay layer is the smallest one of the 6 layers because it has only a thickness of a few centimetres.In exceptional cases such a layer can be up to two metres thick.
The third layer is called Beckenschluff.It came into being in the pleistocene period,too.It's thickness can't be stated exactly,because the "Schluff" is usually in or between the clay layers and has different thicknesses.
Another layer in the Goitzsche is the gravel layer.It also came into being in the Pleistocene period.It can also be found in or between different layers.But general gravel layers have also been found.These layers have an average thickness of 6-7 metres.
The fifth layer is called "Geschiebemergel"and came into being in the Pleistocene  period through alluvail deposits caused melted snow.The thickness of this layer can be about 13 metres.
For the area of Bitterfeld the last and most important layer is the brown coal layer.It is called stratum.These strata came into being in the Tertiary period,strictly speaking in the upper oligocene.The Bitterfeld strata have a thickness of about 19.70 metres.Above the compact coal layer are carbonaceous clay and sand layers which can have a thickness of about 4 metres.

Comment of geological terms

geology: sciene of structure and the development of the earth

earth layers

  • sand: -loose rock with a size of grain of 0.06 up to 2.00 mm
  •  clay: -mixture of different mineral particles with a size of grain < 2 .....m
  •  "Schluff" -loose rock in the size of grain between 0.063 and 0.002 mm
  •  "Geschiebemergel": -through melting glaciers deposited, unlayered mixture of clayey calcareous ingridients and rock (picus/drift)
  •  stratum :-layerly sediments of useful mineral
Present geological era

Concluding table (table)
 

5. Amber
What is amber?

As amber you call compact fossile tree resin of pine wood from the early and middle Tertiary period.Its age can be up to 100 million years.The amber of Bitterfeld belongs to the period between lower and upper miocene.It is nearly 25 million years old.
Amber is a mixture of carbon,hydrogen and oxygen.The collecting formula for amber is (C10 H16 O).

The development of amber 

Amber is an ancient yellow-brown tree resin of extincted pine wood of the Tertiary period.In this time of the geology the resin dripped from the trees onto the forest soil and hardened after 30 to 40 million years to the valuable amber.

Kinds

1. succinite group - succinite, Gedanit, Goitschit
2. Glessit group - Glessit, Bitterfeldit, Purglessit
3. Beckerit group - Beckerit
4. Stanit group - Stantienit, Pseudostandienit

Amber is divided into different groups.The Succinit-,die Glessit-,die Beckerit und die Stanit group.
These groups are divided into different kinds depending on the groups as you can see above.

Amber extraction in Bitterfeld

The reason for extraction was the lack of amber in the VEB "Ostseeschmuck"(jewellery) in Ribnitz-Damgarten in the 1970s.The supply from Russia decreased from 10t to 1t per year.Because of newspaper advertisments Bitterfeld's miners sent amber to Rignitz-Damgarten in 1974.The frequency of contributions caused the VEB "Ostseeschmuck"(jewellery) to give Leipzig geologists the order for a fest mining in Bitterfeld.
 

Utilization of amber
 
sort 1 40% share taleer then 46 mm
sort 2 13% share 20-46 mm
sort 3 50% share 7-20 mm
sort 4 33% share 3-7 mm

All sorts were sold to the  VEB Ostseeschmuck.

The amber mined in Bitterfeld was divided into 4 sorts.All sorts were sold to the VEB "Ostseeschmuck"(jewellery) in Ribnitz-Damgarten.
The sorts 1 to 3 were manufactured jewellery in Ribnitz-Damgarten.

The 4th sort was delivered both to the state-owned enterprise "Ostseeschmuck" (jewellery) and to the state-owned company DELICIA Delitzsch.In Delitzsch the amber was made into either amber oil or colophony rosin.But this brought only little success that's why the 4th sort was made into pressed and liquely....melted amber.

How was amber mined?

Before 1975 amber was still mined by hand.But since 1975 this had been changed.They began with the manual mining of amber on the opencast mining floor,with prospecting hoe and shovel.
From 1976 till 1990 the mechanical production of amber with scoops,dumbers and wet processing plant began in the mining fields Niemegk and Friedersdorf/Mühlbeck.
In 1991 the extraction of amber began in the wet production with a dredger in the mining field Friedersdorf/Mühlbeck.
On 31st March 1993 the amber mining was discontinued.

Mining figures(Chart: amounting of amber)

1975  -mining of amber by hand
-later pilot system for mining

6. Assembly of an opencast mining
To explain the assembly of an opencast mining you must know that there is more than the far visible hole.
As one of the first work the mining field must be examined and surveyed geologically.This work is partly done by the mark aparation.Then you must try to grips with the ground water.For that you mostly take filter wells which are integrated into so-called edge bolt pipes in modern opencast minings.At the same time you must to start with the clearing of the surface.That includes the deforestation of extant forests,the move of streets,overhead lines of electro energy, rivers, streames and so on.
When this has happened, you can start removing the top soil, the upper cover bed.Usually you use smaller bucket wheels or proceedig dredgers for that.This humus soil is normally used for the recultivation of extant dumps of other opencast minings or you sell them to other prospective buyers.The transport of these masses was usually done by train in the area of Bitterfeld.
As a next step the rest of the covers layer was to clear away now.This material was either put into other opencast mining rest holes to recultivate them or it was deposited to a high dump which you can also call outside dump.An example is the hill of Bitterfeld.But if materials, which you could use otherwise, were in these layers of the earth, this was also done.Usefull gravel and sand were delivered to the building industry, for example,or clay was made available for the brickyards.For the task to clear away these covering layer you used bucket chain dredgers in the high or deep cut.
In the Goitzsche were these were the DI 000 and the DI 200.The removed material was also transported by trains.In some opencast minings you also used so-called tram systems for this.The levels of grade on which the big gadgets were located were also called banks.If there was enough exposed of the "Black Gold",its mining could be started.In the Goitzsche you used a bucket wheel dredger SRs250 and for the deep and bucket chain dedgers D800.The coal was also transported by trains from the opencast mining.
To guarantee this train operation,appropriate ramps had to be piled up at the turning point of the opencast minings,because the trains could only overcome a certain gradient.If you got enough off-coaled area,you could start to let the overburden fall into the same opencast mining.The tipping out of the dead material is also called falling and is managed by a depositer.This overburden.....
was also transported to the depositer by train operation in opencast minings.Thus the trains went in semicircle.They were loaded at the dredgers,went to the dpositer,tipped out the rocks into so-called ditches went back to the dredger empty again.This was also called train play.
In opencast mines in which conveyor belts were dominating the dead rocks also came per conveyor belt installation to the depositer, which was regulated by conveyor belt collecting point.
The opencast mine moved slowly because on the one side rock was extracted and on the other side material was tipped out again.You can also say "the opencast mine was wandering". If you extract more from one end,this end will mover faster.Therefore the opencast mine circles.Thus the other end is also called turning point.
Instead of using train or conveyor belt transport it's possible to go the shortest way across the opencast mine if the opencast mine develops parallely. For that you employ overburden conveyor equipment like in the opencast mine Delitzsch South-West. The disadvantage of this technology is that only one limited area of coal stratum can be exposed according to span of the overburden conveyor equipment. This disadvantage is especially obvious at damages or disturbance of big appliance, because you cannot go on working as with other forms of extraction with different excavators.
Not only for this reason we are endeavour to hold the maltunction as small as possible.That's why the maintenance was highly developed and on every big appliance therwas an engineer to settle small repairs on the spot.
To realize the progressing of the opencast mine the railways and conveyor belts installations had to be removed.Conveyor belt installations are usually moved by bulldozers according to miner's style. There are special moving engines for the railway system. The big appliance on track vehicles always had relevant equipment with them.Of course that is not necessary on big appliance and catopillar vehicle.

(2nd version)

The opencast mine is an extraction of useable minerals and rocks, whose natural bed is uncovered or is only covered by relatively thin top layer.
The top soil is taken away to unlock the opencast mine. The overburden ist stored on a dump outside the opencast mine. During the extraction of mineral in the uncovered part the extraction of overburden goes on, so that the extraction can spread to the sides. If a sfficiently big opencast mine has developed by extraction the continuing overburden can be stored in the opencast mine itself.  By this method you can say that the opencast mine moves. Overburdens and minerals are usually extracted terraced whereas the height of the banks depends on the engines used.The opencast mine can be up to 500m deep.
The transportation of the overburdens to the dumps takes place by large-capacity vehicle which are pulled by locomotive on rails or by conveyor belt over an conveyor belt equipment. Instead of railway systems stope belt systems can be used as well.
In the centre of opencast mine you can find the conveyor belt street, which transports coal. At so-called conveyor belt collection points the coal is exposed by sloping conveyor belt systems from the opencast mine and then it is loaded on alternative transportation vehicles (large capacity vehicle, lorry) and transported to the consumers (briquette factory,power station). Under particular geographic conditions this can also be realized by conveyor belt systems (if a power station is near the coal-mine).
 


7.
The geology of the brown coal
The brown coal was mainly formed during two epochs of earth history, namely pit coal in the Carbon and brown coal in the Tertiary period. During the time of the brown coal we can distinguish between 5 different sections. Only two of them have economic importance: the older Eocene and the younger Oligocene and Miocene brown coal. When the older brown coal was formed the today's Northern Germany was covered by a sea. Later its extension increased.In our district the eastern border ran from Delitzsch via Roitzsch, Ramsin, Thalheim and Reuden to Dessau. The Eocene climate, about 50 million years ago, was warm, almost tropical. The flora consists of e.g. palms, dates, bayleaf- and cinamon trees. By lowering land and rising ground-water level the flora and fauna was destroyed. The extendind sea above deposited sand and mud on the destroyed flora and fauna. In the following Oligocene time the sea came from the north overflooding large parts of Germany. In the middle of Oligocene the sea border ran south of Halle and Leipzig. It disappeared and advanced once again in the later Oligocene.The southern border was situated near Aken,  Dessau, Kemberg and Schmiedeberg.The fine deposits like sand, gravel and clay reached a  thickness of up to 20 metres.The numerous findings like shells, shark teeth, fishbones a.s.o. proof the fact that these are really sea deposits. The end of Oligocene  was about 20 to 25 million years ago. During that time the brown coal of the area of Bitterfeld was formed. As we have already said the sea border ran near Dessau-Schmiedeberg. The brown coal forest, which existed in our area, was limited in the west by Brehna, Renneritz,Ramsin, Jeßnitz, Raguhn. The border on the other side of the district was formed today's Mulde river between Krina, Rösa to Gossa and turned  towards the heath. Between Schköna and Lutherstein was a forest reaching to Tornau and Schwemsal in  today's Düben Heath.In the meantime the temperature of the climate decreased and became warm and mild.Because of this the tropical flora disappeared.Conifers and deciduous trees of the temperate climate zone appeared now. The forest mainly consisted of e.g. giant pines, marsh cypresses, alders, maple-trees, poplars and ferns. In the clays depositing above the brown coal  leaves of different trees of the former forest of our native country have been well preserved. In a rare case a pine cone survived millions of years. Sometimes the wood silicified. These pieces are special concrete evidence of the composition of the former forest. You can see such single proofs in the museum. In the past it was assumed that forests forming brown coal had been swamp areas. The present proved the contrary because the giant red woods don't grow in permanently wet or swamp areas. The formation of peat and swamp areas required dryness. This would also supply an explanation for annother fact:  Air roots of subtropical plants couldn't be found in the brown coal although having been searched for eagerly. However we can't be absolutely sure that there were no water plants in these forests at all.
 
 

Because of the lowering land and the rising ground-water level the plant formation began to die slowly. After that, new plants started growing. If there was no lowering land, the fate of the swampland was sealed. The ground-water level rose too fast and transformed the whole place into a lake. The water, which is now flowing above the swampland, covered it slowly with sand and clay. These sea deposits protected parts of the former swampland from decomposition and level down. By this protection the complicated chemical change could start, which is now known as carbonization.Plant material lying in the sea transformed into coal by a kind of hindered burning. The oxygen in the plants was consumed and the carbon was enriched.Results of research from other brown-coal areas showed that to form a one-meter layer of brown coal more than 3000 years were needed. But for Bitterfeld this number only counts approximately. Furthermore the brown coal layers in the district of Bitterfeld generally lie tectonically undisturbed and horizontal. On the contrary, the disturbance by the Ice Age, particularely in the "Dübener Heide" is more important.
The snow water of the glaciers with its whirls has eroded several large parts of strata. On their surfaces the whirl holes can still be seen.Recently, a bigger disturbance of that kind  has been noticed in the opencast mine "Goitzsche". By the pressure-effects of the ice parts the layers were compressed or mixed with sand and clay. This especially happened in the area of the "Gniest" and the "Hohen Gieg" in the "Dübener Heide". The coal deposits in the area of the knee of the Mulde river in Bitterfeld had been eroded and washed away. The river bed of the Mulde poured out from Düben to Bitterfeld and here it turned north to Dessau.In the large curve of the river near Bitterfeld the glacier valley had eroded the sand and  the clay lying above the coals and washed away the coal bed.

 

Contents


1. Introduction
2. Development of coal-mining in the Bitterfeld area until 1900
3. The history of the Goitzsche
4. The geology of the Goitzsche
5. Amber
6. Assembly of an opencast mining
7. The geology of brown coal

  
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