Types of Rock
Types of Rocks
The three types of of rock
IGNEOUS ROCKS - Igneous rocks are formed from the
cooling and solidification of magma or lava.
Example of igneous rocks include
granite, basalt, and obsidian.
SEDIMENTARY ROCKS - Sedimentary rocks are formed from the accumulation and compaction of sediments over time.
Examples of sedimentary rocks
include limestone, sandstone, and
shale.
The process to form sedimentary rocks
1. Weathering
● Rocks are broken down into smaller pieces (sediments) by wind, water, ice, or chemical
processes.
2. Erosion
● The sediments are transported away from their original location by wind, water, or ice.
3. Deposition
● The sediments settle and accumulate in layers, usually in bodies of water like rivers, lakes, or
oceans.
4. Compaction
● Over time, more layers build up, and the weight compresses the sediments below.
5. Cementation
● Minerals in water seep through the layers and "glue" the sediments together, forming solid rock.
METAMORPHIC ROCKS - are formed from the alteration of pre-existing rocks
due to heat, pressure, and chemical processes.
Examples of metamorphic rocks
include marble, slate, and schist.