Diagram of the Rock Cycle Explained

A diagram of the rock cycle is a way to explain the formation, or deformation, of the three types of rocks we find on our earth; sedimentary, metamorphic, and igneous.  The rock cycle picture diagram shows an upper level view of the process in which these types of rocks will be created or transformed.

The rock cycle process flow is not necessarily an ordered set of steps.  The flow of the rock cycle can be bi-directional. It can flow in some other direction and may not only move in one way like many rock cycle diagrams may depict. For simplicity reasons, the rock cycle diagram was created for a general look at the rock cycle.

In this article we want to present a rock cycle explanation and diagram. In particular, we want to explain the rock cycle process with two diagrams to show (above, and in the article below).  This is to help go into some finer detail of understanding of how the rock cycle works.  A little more explanation on the rock cycle can go a long way for both adults and for kids alike.

Sedimentary Rocks in the Rock Cycle

The sedimentary rock cycle is where much of the overall rock cycle action happens.  This part in the diagram of the rock cycle involves much of what’s on the surface of the earth, including the living creatures on it.  The sedimentary rock cycle in the overall rock cycle goes as follows:

• The gathering of sediment – Sediment, or small pieces of rock including other organic material, will make its way to large water locations.  The small rocks are broken off from larger host rocks which can be igneous, metamorphic, and sedimentary.  Depending on what is available on the surface of the earth.
• Traveling of sediment – The sediment is shed from host rocks by weather and other elemental factors such as wind and water.  Plant life and creatures of every kind can additionally assist in the breaking up of rocks.  For the most part wind and water will carry the sediment to its final resting place.
• Settling of sediment in water – Larger bodies of water will collect this sediment on the bottom of its depths to sit there for many years.  Not only small rocks will collect in this final location.  Many plant life, animals, and animal leavings such as fecal matter, scales, or shells will end up in the mix.
• Sedimentary rock creation – As time goes on with all the sediment build up, layers start to form.  Layer upon layer can start to cause mass amounts of pressure on the deeper layers.  A cementation process will happen where the sediment seals itself together to form more solid sedimentary rocks.  

At this point, the sedimentary rock has been formed.  That sedimentary rock can be pushed further into the earth or be brought right back up to the surface to often expose a lot of rocks like sandstone and limestone. 

I have written a great post that goes into further information on sedimentary rocks. “What Are Sedimentary Rocks – Clastic, Biogenic, Chemical“.

The Creation of Metamorphic Rocks

Metamorphic rocks have a little more simple of a process within the diagram of the rock cycle.  When sedimentary rocks receive heat and pressure, and at times the right chemical reactions, they can turn into metamorphic rocks.  This heat and pressure found deep in the earth is necessary for this transformation.

Too much heat, which can create magma, will make the metamorphic rock no longer metamorphic rock.  All materials will be melted down to create the very hot magma that sits within the earth. 

Being melted to magma or mixed with other elements and rocks are not the only fate of metamorphic rock.  Much like sedimentary and igneous rock, it can also be pushed up to the surface of the earth.  Once on the surface of the earth, it can be broken back down into sediment and be subject to the sedimentary part of the rock cycle.

I have written a great post that goes into further information on metamorphic rocks. Metamorphic rocks come in two types… “What are Metamorphic Rocks – Foliated and Non-foliated“.

The Creation of Igneous Rocks

Igneous rocks in the rock cycle diagram carry a uniqueness in that when magma is cooled, the rock is considered an igneous rock.  Even when the contents of the magma were originally metamorphic or sedimentary rocks, when cooled it become igneous rock. 

Igneous rocks can become metamorphic rocks.  This is done by, once again, heat and pressure.  Igneous rocks will mix and meld together under this great heat and pressure.  Not too much heat as was mentioned, we may get magma and only igneous rocks are produced from the magma when cooled.

Igneous rocks while formed under the ground are considered intrusive.  Intrusive igneous rocks are created through a slower cooling process.  This slower cooling allows for beautiful wonders with minerals such as, beryl, topaz, amethyst, and pyrite.

I have written articles on these wonderful examples of minerals where I go into a little more detail about the mineral.

 “All About Red Beryl” (This is one of the rarest, and most expensive, minerals on earth.)

“All About Topaz” (One of the hardest minerals often used for jewelry.)

“All About Amethyst” (This mineral is part of the quartz family.)

“All About Pyrite” (“Fools gold”, could you tell the difference between this mineral and gold?)

Extrusive igneous rocks are created when magma flows up a volcano and lava explodes out onto the surface of the earth.  While this lava is on the surface of the earth it cools quickly forming igneous rock.  A great example of this is with igneous rock obsidian.

I also have a great article on obsidian that might be worth a read. “All About Obsidian” (This rock is very unique as it is often called natures glass.)

With igneous rocks on the surface of the earth, the weather can create sediment from them as they break down, or erode, over time.  This again, will start the sedimentary cycle of the rock cycle.

For more great information on igneous rocks visit my post. “What are Igneous Rocks – Intrusive and Extrusive“.

Rock Cycle Process Summary

The diagram of the rock cycle is a great way to get a quick view of what the rock cycle is. The rock cycle process consists of sedimentary, metamorphic, and igneous rock cycles within. The diagram is helpful but does not go into great detail of all possible directional steps that can happen due to the effects of our earth.

The basic rock cycle steps will include:

• Weathering and Erosion – This is the breakdown of rock material through the weather on our earth.
• Transport and Deposit – Rock material is transported to a final resting point via means of water, wind, gravity, and other.
• Disposition in the Earth – This is where rock material gets buried over time within the earth. This can happen by new layers of rock material on top, earthquakes pulling rock material below, or even pulled under to the depths and flow of sinkholes.
• Heat and Pressure – With pressure comes heat. Heat will change the formation of rocks and minerals. This heat can either change the rock or completely melt it to magma.
• Cooling – When things are heated up, they have the opportunity to cool. Rocks will undergo cooling within the earth and on the surface. During cooling crystallization will occur.
• Rock Resurfacing – This is where rock contents are lifted back up to the surface of the earth. This primarily happens through volcanos pushing up rock material to the surface.

The rock cycle is continuous on our earth.  Mountains become flat, sediment pushes along and deeper into the ground, rocks form underground, and magma pushes everything upward again and creates new mountains. 

This seemingly simple cycle is the foundation of what many geologists would explain as an important reason life existing on our earth.

Importance of the Rock Cycle

The importance of the rock cycle is significant to us in our daily lives.  With the mixture of plant life and the elements of the earth, we have been able to use those rocks in many ways.  They have been an integral part of our economic and industrial development.

Without even some of those rocks, it could be said that our very society, achievements, and advancement would not be where it is today.

The constant renewal of the elements on our earth over long periods of time may seem chaotic and even destructive.  But it must needs be to support and sustain most life on our earth.