The Natural Formation of the Dutch Landscape

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The Natural Formation of the Dutch Landscape
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Formation of the earth

• The earth is 4.5 billion years old.
• The history of the earth is divided into epochs
  geological timescale.
• 0 8000 year Holocene
• 8000 2,5 billion years ago Pleistocene
  (Period with glacials and interglacials)
• The Dutch surface is mainly formed in these two
  epochs.

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Law of Superposition

• Sediments are always deposited on top of each
  other. Therefore the higher, the younger.
• The Netherlands has had different climates. This
  is due to the movements of the plates over the
  world (view BA 52 / 175.
• The Netherlands has always been an area of
  sedimentation.

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Kinds of sedimentation

• Marine sea
• Aeolian wind
• Fluviatile river
• Glacial ice
• Fluvioglacial meltwater
• Organic plants and animals

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Picture 1

• During Carbon uplift of South Limburg, forming
  of relief.
• Pre-Saale period fluviatile sediments
• During colder periods the sea level dropped,
  because large amounts of ocean water was locked
  up as ice. River mouths were more to the West
  than presently.
• The rivers Maas and Rhine were depositing gravel
  and sand during cold periods.
• In some parts up to hundreds of metres.

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Why do ice ages occur?

• Different theories
• Continents move over the earth. Warm or cold
  ocean currents can suddenly cause a temperature
  difference.
• Volcanic activity many ash particles in the air,
  blocking the sunlight.
• Difference in the position of the earth to the
  sun.

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Picture 2

• Ice age Saale glacial important. Hardly any
  vegetation.
• Ice came from Scandinavia.
• Ice reached until the HUN line Haarlem Utrecht
  Nijmegen.
• Push moraines were formed, as well as ground
  moraines (till / boulder clay).
• Problems with impermeability.
• Forming of outwash plains and urstromtäler in
  less cold periods.
• Ice followed the dried-up river valleys.
• Ice retreated in phases, forming low push
  moraines in for example Drenthe.
• Saale land ice pushed the Rhine near Nijmegen to
  a different course, it has a twist to the West.

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Picture 3

• After Saale glacial, Eemien, interglacial. Rise
  in temperature rise in sea level deposit of
  large amounts of sediments (sand and clay).
• Weichsel glacial cold, but land ice did not
  reach The Netherlands.
• Polar desert, permafrost scarce vegetation.
• Aeolian sand deposits loess in South Limburg.
• End of Pleistocene more vegetation sand was
  trapped river dunes.

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Picture 4

• Holocene comes in higher temperatures,
  transgression (fast rise of sea level) more
  vegetation inundations.
• Absolute rise of the sea level heating of the
  sea water melting of ice.
• Relative rise of sea level Weight of ice
  caused a crustal depression near Scandinavia
  uplift of The Netherlands. Holocene melting of
  ice Scandinavian land surface rebounded The
  Netherlands moved downwards again.
• Holocene is a regular interglacial, but
• Large mammals died out. (Mammoth)
• Humans started to influence natural environment.
• Peat bogs (or peat basis)
• Ordinary peat bogs by rainwater
• Raised peat bogs by ground water

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Picture 5

• Lots of peat basis was washed away.
• The coast turned into a waddengebied.
• Marine sedimentations old blue sea clay.
• North Netherlands impermeable till at the
  surface forming of raised peat bogs.
• Central Netherlands fluviatile sedimentation
• River landscape sand particles accumulated along
  edges of river ridges of elevated land built up
  on either side of the river natural levees. In
  lower-lying areas outside the levees (backlands)
  finer clay particles were deposited.
• Presently the levees are relatively higher in the
  landscape due to the settling of the clay in the
  backlands.

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Picture 6

• 5000 years ago Forming of beach-ridges en dunes
• Beach-ridges sand bodies along the coast. Not
  too high, inundate frequently.
• Forming of old dunes.
• Geestgronden old dunes were digged off for the
  production of tulip bulbs.

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Picture 7

• 1000 1200 yrs. after Chr. Forming of young
  dunes.
• Lots of erosion (due to deforestation). Lots of
  sand became available.
• Aeolian sediments young dunes
• Young marine sediments
• Cutting of peat areas
• Humans start to intervene