1. Weathering and Erosion:
- Weathering breaks down igneous rock into smaller pieces (sediments) through various processes like:
- Physical weathering: Freezing/thawing, abrasion by wind or water, or pressure changes.
- Chemical weathering: Reactions with water, oxygen, acids, etc., breaking down the rock's minerals.
- Erosion transports these sediments away from their original location through wind, water, or ice.
2. Transportation and Deposition:
- Sediments are carried by wind, water, or ice, and eventually deposited in a new location, such as a lake, riverbed, or ocean floor.
- Sorting occurs during transportation, with larger, heavier sediments deposited first and smaller, lighter sediments carried further.
3. Compaction and Cementation:
- Layers of sediment build up, creating pressure that compacts the sediments together.
- Cementation occurs as dissolved minerals in groundwater precipitate between the sediment grains, binding them together. These minerals act as a glue, solidifying the sediment into rock.
4. Lithification:
- This is the final stage where the compacted and cemented sediments become a solid sedimentary rock.
Examples:
* Basalt (igneous) can weather and erode into sand, which is transported and deposited, forming sandstone (sedimentary).
* Granite (igneous) can break down into clay particles, which can accumulate and harden into shale (sedimentary).
Key Points:
* Igneous rocks are formed from cooling magma or lava.
* Sedimentary rocks are formed from the accumulation and cementation of sediments.
* The process of transforming igneous rock into sedimentary rock is a long, gradual process.
