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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