Theme 1: Geomorphic Processes (2)

Theme 1: Geomorphic Processes (2)

1. Weathering Processes in Tropics

   • Physical Weathering Process
     • types
       • a) Pressure Release
       • b) Thermal (Insolation) Weathering
       • c) Freeze-thaw (Frost Action)
       • d) Salt Weathering
     • definition
   • Chemical Weathering Process
     • definition
     • types
       • a) Hydrolysis
       • b) Carbonation
       • c) Solution
       • d) Oxidation and Reduction
   • factors affecting weathering
     • Endogenetic
       • a) Rock Strength and Hardness
         • i) Type of bonds
         • ii) Age of rock
       • b) Chemical Composition
       • c) Colour
       • d) Rock Structure and Porosity
         • i) Rock joints
         • ii) Bedding planes
         • iii) Porosity of rock
     • Exogenetic
       • a) Climatic variables
         • Strakhov's diagram
         • i) Precipitation
         • ii) Temperature
         • Peltier's Model
       • b) Relief (Topography)
       • c) Time
       • d) People

2. Karst Landscapes

   • defnition
   • factors influencing karst formation
     • 1) Geology
       • a) Rock type
         • i) Limestone
         • ii) Dolomites
         • iii) Evaporites
       • b) Porosity and permeability
         • i) Primary porosity
         • ii) Secondary porosity
     • 2) Climatic Conditions
       • a) High temperatures
       • b) High rainfall
   • Karst Processes
     • a) Water
       • i) Water arriving at surface and near-surface zones
       • ii) Water that accumulates in vadose zone
       • iii) Water that has reached groundwater table and augmented it
     • b) Weathering on Limestones
       • i) Reaction of carbonic acid with calcite
       • ii) Role of other acids - sulfuric acid
   • Karst Landforms in Tropics
     • a) Cockpit Karsts
       • formation
         • i) Surface solution
         • ii) Underground solution
     • b) Cone, Tower & Isolated Karsts
       • formation
         • i) Transition from cockpit karsts
         • ii) Differential weathering and erosion of rcks
     • c) Karst Valleys
       • i) Blind valley
       • ii) Dry valley
     • d) Caves
       • i) Stalactites
       • ii) Stalagmites
       • iii) Columns