Earth Science - Exogenic Processes (Chapter 7.1-Weathering)
transport
Involves processes by which sediments are moved along from the source to where they are deposited.
Sun's energy
It is energy responsible for exogenic processes, which slowly and steadily tears the landforms down.
Earth's internal heat
It is heat that is much less powerful that of the Sun, and forms the mountains
limestone
It is weathered through dissolution.
Calcite (CaCO3)
it dissloves rapidlyn in acidic water like rainwater
tidal flats
flat, marshy, sandy or muddy areas exposed at low tide and under water at high tide (where most sediment load are deposited)
Solution
movement of soluble minerals (salts).
meander
part of river where deposition occurs
Dissolution
the breaking up or dissolving of something into parts; disintegration. It happens in minerals which are dissolved in water.
Glacial Erosion
the process by which glaciers cut, carve or scratch the earth's surface
frost wedging
the repeated thawing and freezing of water in the cracks of rocks
River bends
where erosion occurs in the river
Saltation
Small pebbles and stones are bounced along the river bed. (Bouncing of sand grains as they are picked-up, carried along and dropped repeatedly.)
Thermal expansion
An increase in the size of a substance when the temperature is increased. When a rock is exposed to high temperature, its outer layer expands due to baking.
biological weathering
Any weathering caused by the activities of living organisms
Hydrolysis
Breaking down complex molecules (polymers) by the chemical addition of water(like digestion). Water reacts with the minerals and breaks them down. It occurs faster in slightly acidic water.
Halite (NaCl)
Compound that dissolves rapidly in pure water
Warm and wet climate
Type of climate good for both chemical and mechanical/physical weathering. Chemical reactions occur at a faster rate.
V-shaped valley
Valleys eroded due to fast flowing water often found in upland areas
biological weathering
Weathering that occurs in roots of plants, when fungi and lichens secrete organic acids that dissolve minerals and the nutrients are taken by these organisms.
Wind erosion
When the wind picks up dirt and dust and moves it from one place to another. It commonly occurs in flat, bare areas or dry, sandy, and loose soils.
Oxidation
A chemical change in which a substance combines with oxygen, oxygen reacts with minerals forming oxides.
Hydration
A chemical weathering process involving water that is added to a mineral, which initiates swelling and stress within the rock, mechanically forcing grains apart as the constituents expand.
Hydration
A chemical weathering process when water is absorbed into the crystal structure of the mineral, causing it to expand.
exfoliation
A mechanical weathering process which removes protuding overlying layers and esposing the weathered down dome of the underlying layers.
exogenic processes
Forces generally originating in the atmosphere that, aided by gravity, shape Earth's surface; erosion by running water, glaciers, wind, and waves are examples It is also driven by solar energy.
Tidal currents
Horizontal flow accompanying the rise and fall of tides
root wedging
In this type of physical weathering, the roots of a plant (typically a tree) wedge into a crack in a rock and, as the plant growns, splits the rock.
Water
Most common erosion agent.
Suspension
Movement of fine particles like silt and clay.
salt wedging
Rock disintegration caused by the crystallization of salts from evaporating water. It usually happens in deserts and along coastal areas.
longshore drift
The movement of water and sediment down a beach caused by waves coming in to shore at an angle. It is the mechanism that transports river sediments along the shoreline.
Weathering
The on-site breaking down of rocks and other materials on the Earth's surface and its eventual transformation into sediments.
Mechanical weathering
The physical disintegration of rock, resulting in smaller fragments without changing its internal composition.
Chemical Weathering
The process in which rock is broken down by changes in its chemical makeup
traction
The rolling or dragging of boulders(large grains) and pebbles along the river bed, aided by the push of smaller grains.
Erosion
The separation and removal of weathered and unweathered rocks and soil from its substrate due to gravity or transporting agents like wind, ice or water.
U-shaped valley
The shape of a valley formed by the erosion of a glacier
exfoliation
Through this, intrusive rocks such as granite usually split into onion like sheets parallel to the surface.