Here's a simplified breakdown:
1. Igneous Rocks:
* Formation: Molten rock (magma or lava) cools and solidifies.
* Types:
* Intrusive: Magma cools slowly underground, forming large crystals (e.g., granite).
* Extrusive: Lava cools quickly on the surface, forming small crystals (e.g., basalt).
2. Sedimentary Rocks:
* Formation: Weathering and erosion break down existing rocks, creating sediments. These sediments are transported by wind, water, or ice and then deposited in layers. Over time, these layers are compressed and cemented together.
* Types:
* Clastic: Formed from fragments of other rocks (e.g., sandstone, shale).
* Chemical: Formed from minerals precipitated from water (e.g., limestone).
* Organic: Formed from the remains of living organisms (e.g., coal).
3. Metamorphic Rocks:
* Formation: Existing igneous or sedimentary rocks are subjected to intense heat and pressure deep within the Earth's crust. These conditions change the mineral composition and texture of the rock.
* Types:
* Foliated: Minerals are arranged in layers (e.g., slate, gneiss).
* Non-foliated: Minerals are not arranged in layers (e.g., marble, quartzite).
The Rock Cycle in Action:
* Igneous to Sedimentary: Igneous rocks are weathered and eroded, forming sediments.
* Sedimentary to Metamorphic: Sedimentary rocks are buried deep within the Earth's crust, exposed to heat and pressure.
* Metamorphic to Igneous: Metamorphic rocks can be melted by heat and pressure, creating magma, which will cool and solidify to form new igneous rocks.
* Sedimentary to Igneous: Sedimentary rocks can also be melted and form igneous rocks.
This is a simplified explanation, but it highlights the cyclical nature of the rock cycle, where rocks are constantly being transformed and recycled over geological timescales.
