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Summary
Geography Class 35

A brief discussion on the previous class (5:10 PM)

Laterization (5:34 PM)

  • It is active in hot and wet equatorial regions.
  • Heavy leaching removes silica and other minerals, except for iron and aluminium, which accumulate at the surface, forming a hard crust.
  • This process is called Laterization.
  • It results in laterite soil.
  • It is slightly acidic.

Podzolization(5:42 PM)

  • It occurs in temperate regions and mountainous regions.
  • The decomposition of coniferous litter releases organic acids.
  • During precipitation, the water mixing through these organic acids creates a strongly acidic solution that removes iron, aluminium, organic matter, and other minerals except silica.
  • This leaves the top layer acidic.
  • It results in podzol soil.

Calcification (5:55 PM)

  • It occurs in regions where evaporation exceeds precipitation.
  • Water rises through capillary action in the soil.
  • It causes the deposition of calcium carbonate in the top layer
  • It is more active in temperate grasslands.
  • It results in the black earth

Salinization

  • It involves the accumulation of highly soluble sodium and magnesium salts, in the topsoil.
  • It is due to excessive evaporation, and very less precipitation.
  • It is active in arid and semi-arid regions
  • It is also common in the regions of flood irrigation.

Gleisation

  • It occurs in water-logged conditions.
  • The colour of topsoil changes due to the reduction reactions.
  • It involves the accumulation of organic matter in the upper layers of the soil.
  • It is common in coastal regions along lagoons and deltas.

Distribution of Soils (6:04 PM)

  • Two types of soil- Pedocal and Pedalfers
  • Pedocal
  • Net upward movement of water
  • evaporation exceeds precipitation
  • Types are Prairie soil, chernozem soil, chestnut soil, Desert soil
  • Pedalfer
  • Net downward movement
  • Precipitation exceeds evaporation
  • Types are Laterite soil, red soil, Podzol soil
  • USDA Classification
  • Entisol Fresh Alluvium
    Inceptisol Old alluvial, volcanic soil
    Spodosol Podzol soil
    Alfisol Leached Soil with Al and Fe
    Ultisol Leached Soil 
    Oxisol The top layer is weathered with rich Al and Fe
    Vertisol Black Soil
    Histosal Peaty Soil rich in Organic Matter
    Mollisol Prairie Soil
    Aridisol Desert Soil

Mapping (6:18 PM)

  • Europe
  • Seas: Mediterranean Sea, Adriatic Sea, Black sea, Caspian sea
  • Mountains: Ural mountains, Alps mountain, Caucasus mountain, Mt Elbrus
  • Countries: Vatican City
  • Cities: Istanbul, Rome
  • North America:
  • Sea:  Californian bay, Gulf of Mexico, Bering sea
  • Mountains: Rocky Mountains, Appalachian mountains, Mt Denali
  • Places: Death Valley
  • Latin America: Except for Greenland, Canada, and USA, all other countries in the North and South American continent.
  • South America
  • Places: Drake Passage, Valdes Peninsula, Angel falls
  • Mountains: Andes Mountains, Mt Aconcagua, Ojas del salado
  • Rivers: Amazon, Lake Orninoco
  • Oceania (7:18 PM)
  • Countries: Australia, New Zealand
  • Island groups are divided into Micronesia, Melanesia, and Polynesia
  • Micronesia includes Caroline Island, Kiribati, etc
  • Melanesia includes New Guinea, Fiji, etc
  • Polynesia includes Hawai, New Zealand, Tonga island, Easter Island
  • Places: Great Dividing Range, Great Barrier Reef, Mt Wilhelm, Southern Alps
  • Antarctica
  • Antarctic treaty System, 1961 held that Antarctica can be used only for peaceful experiments.
  • The base stations of India in Antarctica are Dakshin Gangotri, Maithri, and Bharati.
  • India (7:38 PM)
  • We have both land and maritime neighbours.
  • Land Neighbours are Pakistan, Afghanistan, China, Nepal, Bhutan, Bangladesh, and Myanmar.
  • Afghanistan shares a border with India along Wakhan Corridor.
  • Countries arranged in order of length of the border with India: Bangladesh(4000 km)> China(3500 km)>Pakistan(3300 km)>Myanmar(1700 km)>Nepal(1650 km)>Bhutan(700 km)>Afghanistan(100 km)
  • Countries with maritime boundaries: Bangladesh, Pakistan, Myanmar, Sri Lanka, Maldives, Indonesia, Thailand
  • Union territories of India: Andaman and Nicobar islands, The Government of NCT of Delhi, Ladakh, Puducherry, Lakshadweep, Jammu and Kashmir, Chandigarh, and Dadra and Nagar Haveli and Daman and Diu.
  • The highest peak in India is K2 and the Second highest peak is Kanchenjunga
  • The lowest point in India is in Kuttanad (Kerala)

The topic for the next class: Physical geography of India