Goh Cheng Leong: Chapter 2 YouTube Lecture Handouts Geography
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Goh Cheng Leong Chapter 2: The EarthΥs Crust (Physical and Human Geography)
Certificate Physical & Human Geography Goh Cheng Leong
Chapter 2: The EarthΥs Crust
Structure of Earth
- Crust
- Mantle
- Core
Rock Classification - Igneous
- Magma
- Crystalline
- No layers
- No fossils
- Silica β Acid, less dense & light
- Fe, Al & Mg β Basic, dense & dark
- Plutonic β at depth, cool and solidify slowly β intrusive (granite, diorite & gabbro)
- Volcanic β lava, rapid solidify, small crystals, basalt, extrusive
- Basalt β polygonal columns in Giant Causeway Antrim (N. Ireland) , Deccan (India) , Columbia-Snake (USA) β Dyke () & Sills ()
- Hard & resistant
- Road making and monuments
Rock Classification - Sedimentary
- Sediments
- Layers
- Stratified
- Non-crystalline
- Fossils
- Mechanically: cemented together, sandstone β coarse (grit) ; round (conglomerate) ; angular (breccia) ; fine β clay & mudstone
- Organically: living organisms, calcareous (limestone & chalk) ; carbonaceous (swamp & forest) β coal (peat, lignite and coal)
- Chemically: rock salt (seabeds) , gypsum or - Dead Sea, Potash & nitrates
Rock Classification - Metamorphic
- Changed
- Pressure and heat
- Clay Slate
- Limestone Marble
- Sandstone Quartzite
- Granite Gneiss
- Shale Schist
- Coal Graphite
Mountain Orogeny
Types of Mountains -Fold
- Fold Mountain β stress and wrinkles, fold on line of weakness, mountains of elevation
- Overfold, Recumbent and nappe
- Volcanic (Circum Pacific)
- Sn, Cu, Au & petroleum
Types of Mountains -Block
- Faulting β Tension or Compression
- Horst or block
- Garben or rift
- Tension β Hunsruck, Vosges & Black Forest, East African Rift Valley β Major (subside)
- Compression β Thrust or reverse fault (uplift)
Types of Mountains -Volcanic
- Lava, bomb, cinder, ash, dust
- Mountain of accumulation
- Mt. Fuji (Japan)
- Mt. Mayon (Philippines)
- Mt. Merapi (Sumatra)
- Mt. Agung (Bali)
- Mt. Catopaxi (Ecuador)
Types of Mountains -Residual
- Denudation
- Mt. Manodrock (USA)
- Dissected Plateaux β downcutting β Scotland, Scandinavia and Deccan
Types of Plateaux - Tectonic
- 4 Tablelands
- Earth movements
- Deccan (India)
- Tilted β Meseta (Iberia)
- Faulted β Harz (Germany)
- Intermont β b/w 2 mountains (Tibetan b/w Himalayas and Kunlun; Bolivia b/w Andes)
Types of Plateaux - Volcanic
- Basaltic β lava β solidify
- Antrim (N. Ireland)
- NW Deccan (India)
- Columbia-Snake (USA)
Types of Plateaux - Dissected
- Weathering and erosion
- Deep cuts
- Stream and glacial actions
- Scottish Highlands
- Mesa and butte (SW USA)
- Brazilian plateau (Minas Gerias) β Fe & Mn
- Deccan β Mn, Fe and Coal
- W. Australia β Au & Fe
Types of Plains
- Area of lowland
- Low hills with rolling topography
- Indo-Gangetic plain
- Mississippi plains
- Yangtze plain
- Grasslands
- Russian β Steppes
- N. America β Prairies
- Argentina β Pampas
- Structural β structurally depressed and lowlands β Russian, Great Plains and lowlands of Australia
Types of Plains - Depositional
- Deposition by various agents
- Rivers β alluvial plains, flood plains and deltas
- Nile, Egypt: Rice and cotton
- Ganga, India: jute and rice
- Hwang Ho, China: many crops
- Glacial β outwash plains (boulder clay) β barren β Holland and N. Germany; Midwest USA; East Anglia (England)
- Coastal - waves and winds β Belgium, Netherlands, Gulf coast of USA (lowlands) & Florida to Texas (uplands)
- Aeolian β loess β China, Pampas- fill grooves
Types of Plains - Erosional
- By agents of erosion β wind, water, rain, ice
- Plains of denudation β peneplains (humid)
- River deepen and widen (highlands are lowered)
- Glaciated β ice-scoured plains β hollows scoop out ice and filled with water; Finland β 35,000 lakes with 10% area
- Wind β deflation β eroded material; stony plains β reg in Africa β mountains with gentle slope pediments and pediplains (arid & semi-arid with inselbergs- steep hills)
β Manishika