The science that deals with the earth's physical structure and substance, its history, and the processes that act on it.


The 3 main types of rocks are...
  • Igneous: Formed by the cooling of magma.
  • Metamorphic: Formed by heat and pressure.
  • Sedimentary: Formed by compacting.
Igneous Rock Facts

  • The word 'Igneous' comes from the Latin word ‘Ignis’, which means fire.
  • Many roads are made from crushed igneous rock .
  • There are over 700 different types of igneous rocks.
  • Igneous rocks contain many minerals that help plants grow.
  • Most of the earth’s crust is made out of igneous rock.
  • Most of the earth’s crust is made out of igneous rock.

Metamorphic Rock Facts

  • Uplift and erosion help bring metamorphic rock to the Earth's surface
  • Metamorphic rocks have been changed over time by extreme pressure and heat.
  • These rocks are classified by their textures.
  • Metamorphic rocks cannot contain fossils as the high pressure in the rock as well as high temperatures erases the fossils.

Sedimentary Rock Facts

  • Primary sedimentary structures (bedding, lamination, ripple marks) are formed during sediment deposition, where secondary structures (trace fossils, sole marks, mudcracks) are formed after sediment deposition
  • The sediment is compressed over a long period of time before consolidating into solid layers of rock
  • Sedimentary rocks are formed through deposition, solidification, compacting and erosion of sediment which is reffered to weathering.


Rocks are classified by how they are formed.

Types of Rocks & Rocks Cycle Video for Kids by


The rock cycle is a cycle that displays all the 3-5 different types of rocks (sedimentary, igneous, metamorphic, sediment and magma) and how they are formed.

What could happen to a rock after a million years?

After a million years, a rock would repetitively transform into all the different formations that is inside the rock cycle. All this would be caused by certain effects... e.g. compacting, melting, cooling, weathering and heat/pressure.


There are 6 types of ways rocks can form and they are...

  • Melting
  • Cooling
  • Heat/pressure
  • Compacting
  • Weathering
Rocks Cycle video for Kids by


The Earth's structure consist of 4 layers and they are...
  • Crust: 0-100km thick, solid and 56-398 degrees celsius.
  • Mantle: 2900km thick, solid and 1000-2500 degrees celsius..
  • Outer Core: 2200km thick, liquid and 4000 degrees celsius..
  • Inner Core: 1200km thick, solid and 5000 degrees celsius.


Even though the inner core is the hottest part of the Earth, the pressure is so great it stays in the form of a solid.

Structure of the Earth


  • The difference between magma and lava is that magma is found below the surface of the Earth while lava is found at the surface.
  • The difference between intrusive and extrusive rocks is that intrusive rocks are formed below the surface of the Earth while extrusive rocks are formed at the surface.
  • The difference between a dike and a sill is that dykes are formed across or vertical to the rock while sill is on horizontal cracks. However, they are both sedimentary in nature.