What are Rocks?
Rocks consist of minerals, organic materials, and other rocks. The three main types of rocks are Igneous, Metamorphic, and Sedimentary.
Igneous Rocks:
Cooling magma
Intrusive-when cooling takes place slowly beneath Earth’s surface. Form large crystals (Granite).
Extrusive-when cooling takes place rapidly on Earth’s surface. Form small mineral crystals and a fine texture (Basalt/Obsidian).
Metamorphic Rocks:
Heat and Pressure
Rocks are heated, squeezed, folded, or chemically changed by contact with hot fluids inside of Earth.
Metamorphic rocks form from other rocks.
Sedimentary Rocks:
Compacting sediments
Rocks form when other rocks weather and erode into sediment. This sediment is then deposited and compacted to form sedimentary rocks.
Fossils can be found in sedimentary rocks.
Conglomerate Rocks: a combination of two or more types of rock. This can happen when chunks of rock get mixed in with sediment that compacts.
Igneous Rocks:
Cooling magma
Intrusive-when cooling takes place slowly beneath Earth’s surface. Form large crystals (Granite).
Extrusive-when cooling takes place rapidly on Earth’s surface. Form small mineral crystals and a fine texture (Basalt/Obsidian).
Metamorphic Rocks:
Heat and Pressure
Rocks are heated, squeezed, folded, or chemically changed by contact with hot fluids inside of Earth.
Metamorphic rocks form from other rocks.
Sedimentary Rocks:
Compacting sediments
Rocks form when other rocks weather and erode into sediment. This sediment is then deposited and compacted to form sedimentary rocks.
Fossils can be found in sedimentary rocks.
Conglomerate Rocks: a combination of two or more types of rock. This can happen when chunks of rock get mixed in with sediment that compacts.
The Rock Cycle
This is an ongoing process that changes rocks from one type to another. The image below shows the process of each rock formation.