1. Physical Weathering: This is the initial breakdown of the granite into smaller pieces. The most common forms for granite include:
* Frost Wedging: Water seeps into cracks, freezes, expands, and widens the cracks.
* Thermal Expansion/Contraction: Daily temperature fluctuations cause the rock to expand and contract, creating stress and fracturing.
* Abrasion: Rocks are rubbed against each other by wind, water, or ice, breaking them down.
2. Chemical Weathering: This involves changes to the chemical composition of the granite. The most common for granite are:
* Hydrolysis: Water reacts with minerals in the granite, altering their composition.
* Oxidation: Iron minerals in the granite react with oxygen, creating rust (iron oxide) and weakening the rock.
* Carbonation: Carbon dioxide in rainwater forms carbonic acid, which reacts with calcium-containing minerals in the granite, dissolving them.
3. Biological Weathering: This is the breakdown of granite due to living organisms. Examples include:
* Plant Roots: Roots growing into cracks can exert pressure and widen them.
* Lichen and Algae: These organisms can produce acids that weaken the rock.
4. Erosion: Once the granite is broken down into smaller pieces, these pieces are moved by natural forces. The most common forms for granite are:
* Water Erosion: Rivers, streams, and ocean waves carry away eroded granite.
* Wind Erosion: Wind picks up small pieces of granite and transports them.
* Glacial Erosion: Glaciers can carve out valleys and carry large amounts of granite.
5. Transportation and Deposition: Eroded granite pieces are carried to new locations and eventually deposited. The final location of these pieces depends on the transporting force.
Important Note: These processes are interconnected and often occur simultaneously. For example, physical weathering creates more surface area for chemical weathering to act on. The resulting weathered and eroded material can then be transported and deposited elsewhere, forming new landforms and contributing to the ongoing cycle of rock formation and erosion.
