The ROCK CYCLE and types of rock and major geological processes

KS3 SCIENCE QUIZZES and WORKSHEETS (~US grades 6-8)

KS4 Science GCSE/IGCSE CHEMISTRY NOTES (~US grades 8-10)

KS4 Science GCSE/IGCSE CHEMISTRY QUIZZES and WORKSHEETS (~US grades 8-10)

KS4 Science GCSE/IGCSE CHEMISTRY SYLLABUS HELP LINKS (~US grades 8-10)

ADVANCED LEVEL CHEMISTRY NOTES (~US grades 11-12)

ADVANCED LEVEL CHEMISTRY QUIZZES and WORKSHEETS (~US grades 11-12)

ADVANCED LEVEL CHEMISTRY SYLLABUS HELP LINKS (~US grades 11-12)

Doc Brown's Chemistry - Earth Science Revision Notes

2. The Rock Cycle

Revision KS4 Science IGCSE/O level/GCSE Chemistry Information Study Notes for revising for AQA GCSE Science, Edexcel 360Science/IGCSE Chemistry & OCR 21stC Science, OCR Gateway Science (revise courses equal to US grades 9-10)

based on a GCSE Geological & Earth Science TASK SHEET * Earth Science Homepage * 5 multi-word fill GCSE worksheets + answers * GCSE Earth Science Quiz: Foundation-easier m/c Quiz and Higher-harder level m/c Quiz

ANSWERS-NOTES 1. The Evolution of the Earth's atmosphere and Carbon Cycle ... 2. The Rock Cycle and types of rock (details 'evolve' through sections 3. to 9.) ... 3. Weathering of Rocks ... 4. Igneous Rocks ... 5. Sedimentary Rocks ... 6. Metamorphic Rocks ... 7. The Structure of the Earth ... 8. Plates and their movement ... 9. Plate Tectonics ... 10. The Moon and Planets

2. The Rock Cycle The "1st Big Picture View"

Many of the features of the rock cycle are illustrated below in Fig 2.1 The Rock cycle. (see also Fig 8.1 and Fig 9.2)

doc b's Earth Science Notes Fig 2.1

Sections 3. to 9. take you through all the details.

Rocks are classified into groups of IGNEOUS, METAMORPHIC and SEDIMENTARY ROCKS depending on their origin.

All rocks have crystalline structure based on giant ionic or covalent structures (Chemical Bonding Notes)
Physically they are relatively insoluble in water, poor heat and electrical conductors and have high melting points. They are generally hard materials but with quite some variation between rock types e.g. softer limestone (easily weathered) and much harder basalt rocks used for street cobbles.
Generally speaking, igneous rocks like granite and basalt are much harder and 'weather resistant' than sedimentary rocks like limestone, shale and sandstone which erode much more easily. Rock type details are given in 4. to 6. below.
The three generalised type of rock are discussed in detail in sections 4. to 6.
- Section 4. Igneous rocks are formed from cooled molten magma or lava from the Earth's mantle below the crust.
- Section 5. Sedimentary rocks are formed deep in the Earth's crust from highly compressed deposits of weathered rock material or mineral deposits from plants and animals.
- Section 6. Metamorphic rocks are formed from re-existing sedimentary or igneous rocks by the action of heat and pressure deep underground in the Earth's crust.

Below is a simpler approach to the "THE ROCK CYCLE" to show the relationship between the three types of rocks

doc b's Earth Science Notes Fig 2.2

By the end you should be able to identify, describe and understand the processes shown in the diagram.

[e] - after erosion [ g ], transportation by eg water at [ f ], sedimentation [ h ], the sediments are buried by successive layers under pressure to cause cementation at [ e ], so sedimentary rock is formed eg sandstone

[f] - after erosion [ g ], transportation by eg water at [ f ], sedimentation [ h ], the sediments are buried by successive layers under pressure to cause cementation at [ e ], so sedimentary rock is formed

[g] - weathering and erosion occur more readily in mountainous areas [ g ], followed by transportation [ f ], sedimentation [ h ], cementation at [ e ] to form sedimentary rocks

[h] - weathering and erosion occur more readily in mountainous areas [ g ], followed by transportation by water usually [f ], sedimentation [ h ], cementation at [ e ] to form sedimentary rocks

[k] - magma rises from the mantle at [ n ] and pours out in volcanic activity on land (and under the sea), this causes rapid cooling at [ k ] and igneous rocks of small crystals like basalt are formed

[l] - magma rises from the mantle at [ n ] and if it slowly crystallises at [ l ] and forms igneous rocks with large crystals like granite

[m] - deep lying rocks are under pressure or heated near the mantle can recrystallised to form metamorphic rocks at [ m ]

[n] is where magma rises from the mantle (may pour out as lava at [ k ]) or deep lying rocks get heated and melt into the mantle (destroying any fossils - not found in igneous rocks!, can also be destroyed at [m]

Its a 'balanced' global cycle both internally and externally! Mountain ranges get pushed up, continents form, then the crust gets subducted and if not subducted, mountain ranges still get worn away by weathering and erosion ...

.... so everything gets recycled in the end!