Earth Surface Processes in the Mediterranean Basin

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  • Created by: nicola
  • Created on: 05-04-11 19:45

Minimal human impact on the landscape prior to 5000 yrs ago - seen all over the world

Humans clearing landscape in Mediterranean longer than in other areas, large populations exist in developed societies (for many 000's yrs)

Europe 4000 yrs ago was mainly covered in woodland - contrasts to records from Mediaeval period across the Med - woodland restricted to mountainous regions - not yet cleared

Affects stability of land surface and sediment production

Also has affects on:

  • Soils - need stability for formation
  • Slopes - de-vegation causes instability
  • Rivers - sediment supply

Soils

Climate is main affecting factor but steep slopes due to mountainous terrain and aeolian inputs (dust from Sahara) impact as well 

Limestone bedrock most common underlying bedrock due to basin morphology (infill with softer seds)

Soils form in warm and moist climates

Alternating between dry and wet seasons produce unique characteristics:

  • Red, clay rich soils - Terra Rosa - 
    • Thick profiles
    • Dominated by iron and clay accumulation - produced by woodland vegetation which weather sediments to clay
    • Need warm moist climates that persistent for long periods to induce formation
    • Form during interglacials
    • Down profiling/ translocation of clay minerals occurs during wet autumn/ winter producing a clay rich horizon at depth of wetting (above water table)
    • Oxidation of this horizon occurs to form iron oxide in dry summers as it dries out the soil profile 
    • Warm temps all yr cause haematite to form hence the red colour
    • Form in wetter parts of Med
  • Calcrete horizons - 
    • Seasonal wetting promotes dissolution of carbonate in upper soil horizons 
    • Leads to translocation of dissolved carbonate down through the profile
    • This is re-precipitated lower in the profile - requires seasonal dryness 
    • Temperatures are not important
    • Form in drier…

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