Types of Rocks Igneous-Sedimentary-Metamorphic Rocks

Summary

This video from moomoomath and science explores the fascinating world of rocks, categorizing them into three main types: igneous, sedimentary, and metamorphic. It delves into the formation of rocks like obsidian, granite, and basalt, and explains how sedimentary rocks like sandstone and limestone are created. The video also covers metamorphic rocks, which transform from existing rocks under heat and pressure, showcasing examples like slate and marble. It's an informative journey through the natural history of our planet's crust.

Takeaways

• 🌋 Rocks are naturally occurring solid materials made up of minerals or mineral-like matter.
• 🏔 Rocks can be categorized into three main types based on their formation: igneous, sedimentary, and metamorphic.
• 🔥 Igneous rocks are formed from the cooling of magma or molten rock, and are divided into extrusive (volcanic) and intrusive (plutonic) based on where they cool.
• 💎 Obsidian is an extrusive igneous rock with a glass-like appearance and a hardness between 6 and 7.
• 🗻 Granite is an intrusive igneous rock with medium to coarse grain crystals and a hardness of 5 to 5.5.
• 🌑 Basalt is a dark, dense extrusive igneous rock with a hardness between 5 and 6, composed of plagioclase, feldspar, and pyroxene.
• 🌋 Scoria is a volcanic igneous rock similar to basalt but with cavities filled with other minerals.
• 🏞️ Sedimentary rocks are formed from the accumulation of sediments, which can be clastic, chemical, or organic in nature.
• 🐚 Shell is a fine-grained clastic sedimentary rock composed of mud, a mix of clay minerals and silt-sized particles.
• 🏜️ Sandstone is a common clastic sedimentary rock made up of sand-sized grains of mineral or organic material.
• 🌊 Limestone is an organic sedimentary rock composed of marine organism skeletons, making up about 10% of sedimentary rocks on Earth.
• 🔥 Metamorphic rocks result from existing rocks being subjected to extreme heat and pressure, changing their original structure.
• 💼 Slate is a foliated metamorphic rock with very small minerals, derived from shale.
• ⚫ Marble is a non-foliated metamorphic rock with fine to medium crystals, originating from limestone.
• 🏜️ Quartzite is a non-foliated metamorphic rock formed from sandstone.
• 🌲 Schist is a foliated metamorphic rock with a parent rock of schist.

Q & A

What are the three basic types of rocks mentioned in the script?

The three basic types of rocks mentioned are igneous, sedimentary, and metamorphic.

How are igneous rocks formed?

Igneous rocks are formed when magma or molten rock cools. They can either be extrusive or intrusive, depending on whether they cool on the surface or within the Earth.

What is the main difference between extrusive and intrusive igneous rocks?

Extrusive igneous rocks cool quickly on the surface of the Earth and generally have very small crystals, while intrusive igneous rocks cool slowly inside the Earth and have larger crystals.

What is obsidian and what are its characteristics?

Obsidian is an igneous extrusive or volcanic rock made up of quartz, alkali, and feldspar. It looks a bit like glass and has a hardness between 6 and 7.

What is the composition of granite and what type of igneous rock is it?

Granite is an igneous intrusive rock composed of feldspar, quartz, and mica. It has medium to coarse grain crystals and a hardness between 5 and 5.5.

How are sedimentary rocks formed and what are they made of?

Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They are made from deposits that accumulate on the Earth's surface or under the ocean, which are called sediment and may be composed of minerals or organic matter.

What are the common groups of sedimentary rocks?

Common groups of sedimentary rocks include clastic sedimentary rocks, chemical sedimentary rocks, and organic sedimentary rocks such as coal and limestone.

What is shale and how does it differ from other clastic sedimentary rocks?

Shale is a fine-grained clastic sedimentary rock composed of mud, which is a mix of flakes of clay minerals and silt-sized particles of other minerals, especially quartz and calcite. It differs from other clastic sedimentary rocks in its very fine grain size.

What is the process of precipitation in the context of chemical sedimentary rocks?

In the context of chemical sedimentary rocks, precipitation is the process by which dissolved minerals come out of water.

How are metamorphic rocks formed and what can they originate from?

Metamorphic rocks are formed from existing rocks that are subjected to extreme heat and pressure, which changes their original structure into a new type of rock. They can originate from sedimentary, igneous, or even other metamorphic rocks.

What are the two major types of metamorphic rocks and how do they differ?

The two major types of metamorphic rocks are foliated rocks, which have crystals in stripes, and non-foliated rocks, which do not have crystals in stripes.

What is the parent rock of slate and what type of metamorphic rock is it?

The parent rock of slate is shale, and it is considered a foliated metamorphic rock.