GeographyISC Class 11 · Rocks

Sedimentary and Metamorphic Rocks and the Rock Cycle (ISC Class 11 Geography)

Updated 17 October 2026 · Fact-checked

Sedimentary rocks form when weathered fragments are deposited in layers and cemented; they are mechanical (sandstone), organic (limestone, coal) or chemical (rock salt). Metamorphic rocks form when heat and pressure change existing rocks, as limestone becomes marble. The rock cycle links all three with igneous rocks and magma.

Follow the arrows: sedimentary rock comes from weathered fragments laid in layers, and heat and pressure turn it into metamorphic rock.

Illustration drawn for QuestionBuddy.

Understand Sedimentary and Metamorphic Rocks and the Rock Cycle

Sedimentary rocks. Rocks are weathered and eroded; rivers, wind, ice or sea carry the fragments and deposit them in layers, which are then compacted and cemented (lithification).

Mechanically formed (clastic): sandstone, conglomerate, shale, loess.
Organically formed: limestone and chalk from shells and skeletons, coal from plant remains.
Chemically formed: rock salt and gypsum, precipitated from water.
Features: layered (stratified), may hold fossils, usually softer and more porous than igneous rocks; they cover most of the land surface but form a small part of the crust by volume.
India: alluvium of the Indo-Gangetic plains; Vindhyan sandstone and limestone in Madhya Pradesh and Rajasthan; Gondwana coal in the Damodar, Mahanadi and Godavari valleys (Jharia, Raniganj).
Uses: coal and petroleum, limestone for cement and steel-making, sandstone for building, porous layers hold groundwater.

Metamorphic rocks. Existing igneous or sedimentary rocks are changed in texture and minerals by heat, pressure or both, without melting completely.

Contact (thermal) metamorphism: rock baked next to intruding magma. Regional (dynamic) metamorphism: heat and pressure over large areas during mountain building.
Changes: limestone to marble; sandstone to quartzite; shale to slate and with more heat and pressure schist; granite to gneiss.
Features: harder and more compact, minerals often in bands (foliation), fossils usually destroyed.
India: marble at Makrana in Rajasthan; slate in Himachal Pradesh; gneiss, schist and quartzite in the old Peninsular rocks and Aravallis.

Rock cycle. Magma cools to igneous rock; weathering and deposition give sediments; compaction gives sedimentary rock; heat and pressure give metamorphic rock; deep melting gives magma again. Short cuts exist: any rock can be uplifted and weathered, igneous rock can be metamorphosed directly. Internal heat drives melting, metamorphism and uplift; the sun drives weathering and erosion.

Sedimentary and Metamorphic Rocks and the Rock Cycle: key facts

Sedimentary types: Mechanical sandstone, shale
Organic limestone, coal
Chemical rock salt, gypsum
Metamorphic changes: Limestone to marble
Sandstone to quartzite
Shale to slate
Granite to gneiss
Rock cycle: $M a g ma ∣ I g n eo u s ∣ S e d im e n t s ∣ S e d im e n t a r y ∣ M e t am or p hi c ∣ M a g ma$; Short cuts are possible.

Mechanical	sandstone, shale
Organic	limestone, coal
Chemical	rock salt, gypsum

How to answer Sedimentary and Metamorphic Rocks and the Rock Cycle questions

Expect 4-mark distinctions and 7-mark two-part answers on formation, types and the rock cycle.

1State how the rock forms in one sentence.
2List types with an example each, then features.
3Add Indian distribution and uses with named regions.
4For the rock cycle, write the stages in order and mention short cuts and the driving forces.

Sedimentary and Metamorphic Rocks and the Rock Cycle in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Layers record time

Suppose a cliff shows ten flat layers, the lowest holding shell imprints and the upper ones holding none.

What kind of rock is this and what does the order tell us?

Try it first, then show the solutionSolution

Layers and fossils indicate sedimentary rock formed by deposition.
The lowest layer was deposited first, so it is the oldest.

Answer: Sedimentary rock; the lowest layer is oldest.

Memory hook: Layers are pages in a stack.

Baking a rock

Suppose a limestone bed lies next to a hot magma intrusion and, near the contact, turns hard, crystalline and white.

Name the process and the rock formed.

Try it first, then show the solutionSolution

Heat from nearby magma alters the rock: contact metamorphism.
Limestone changes to marble.

Answer: Contact metamorphism forming marble.

Memory hook: Heat bakes limestone into marble.

Tricks to remember Sedimentary and Metamorphic Rocks and the Rock Cycle

Short memory aids. Say each one aloud once, then use it on a question the same day.

Three origins
Mechanical (broken pieces), Organic (living remains), Chemical (dissolved salts).
Use it when: Sedimentary classification.
Change pairs
Lime-Marble, Sand-Quartzite, Shale-Slate, Granite-Gneiss.
Use it when: Metamorphic examples.
Cycle loop
Cool, Break, Bury, Squeeze, Melt: then cool again.
Use it when: Rock cycle order.

Sedimentary and Metamorphic Rocks and the Rock Cycle: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Marble source · 1 mark · MCQBoard level

Marble is formed by metamorphism of which rock?
(a) Sandstone
(b) Shale
(c) Limestone
(d) Granite

Try it first, then show the solutionSolution

Carbonate rock limestone is changed by heat.

Answer: (c) Limestone.

Example 2: Sedimentary classification · 3 marks · Short answerBoard level

Classify sedimentary rocks by formation with an example of each.

Try it first, then show the solutionSolution

Mechanical: sandstone or shale.
Organic: limestone or coal.
Chemical: rock salt or gypsum.

Answer: Mechanical (sandstone), organic (coal) and chemical (rock salt).

Example 3: Contact and regional · 4 marks · Long answerHarder board level

A shale bed beside a magma body and another shale bed deep in a rising mountain belt both turn into new rocks. Compare the two processes and name the likely product in the mountain belt.

Try it first, then show the solutionSolution

Beside the magma the change is contact (thermal) metamorphism, caused by local heat.
In the mountain belt the change is regional (dynamic) metamorphism, caused by heat and pressure over a wide area.
The scale differs: a narrow baked zone versus large belts.
The shale in the belt is likely to become slate and, with more heat and pressure, schist.

Answer: Contact metamorphism is local and thermal; regional metamorphism is wide and uses heat and pressure. Shale in the mountain belt becomes slate or schist.

Example 4: Rock cycle journey · 4 marks · Long answerHarder board level

Describe a path by which a granite body could become a metamorphic rock and then an igneous rock again.

Try it first, then show the solutionSolution

Granite is exposed to heat and pressure when buried or caught in mountain building and becomes gneiss.
This is a short cut: igneous to metamorphic with no sediment stage.
At great depth gneiss melts to magma.
The magma cools and solidifies to new igneous rock.

Answer: Granite to gneiss by metamorphism, then gneiss melts to magma, which cools to new igneous rock.

Example 5: Evaluate the statement · 5 marks · Long answerHOTS / competency

"No rock on earth is permanent." (a) Explain with the rock cycle. (b) Name the two energy sources that drive it. (c) Explain why sedimentary rocks cover most land yet form a small part of the crust.

Try it first, then show the solutionSolution

(a) Each rock can be weathered to sediment, metamorphosed or melted, becoming another type.
(b) Earth's internal heat for melting, metamorphism and uplift; the sun for weathering, erosion and deposition.
(c) They form a thin surface veneer over a crust that is mostly igneous and metamorphic.

Answer: (a) Rocks keep changing type (b) internal heat and the sun (c) sedimentary rocks are a thin surface layer.

Where students lose marks in Sedimentary and Metamorphic Rocks and the Rock Cycle

The slips examiners see most often, and what to write instead.

Mistake: Saying metamorphic rocks form by melting
Confusion with igneous formation.
Do this: Metamorphic rocks change in the solid state under heat and pressure; complete melting makes magma.
Usually costs: 1 mark.
Mistake: Wrong pairs such as sandstone to marble
Parent rocks are swapped.
Wrong working
Sandstone to marble
Right working
Sandstone to quartzite; limestone to marble
Do this: Learn limestone-marble, sandstone-quartzite, shale-slate, granite-gneiss.
Usually costs: 1 to 2 marks.
Mistake: Writing the rock cycle without short cuts
Only the one-way loop is shown.
Do this: Mention at least one short cut such as igneous to metamorphic.
Usually costs: 1 mark.

Exam tips

Write the rock cycle as numbered stages and add one short cut.
Name an Indian region for each rock type.
Use the word foliation for banded metamorphic rocks.
Keep sedimentary classification to mechanical, organic, chemical.

Practice questions on Sedimentary and Metamorphic Rocks and the Rock Cycle

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which pair correctly shows a sedimentary rock formed from living remains?
(a) Granite and basalt
(b) Limestone and coal
(c) Marble and slate
(d) Rock salt and gypsum
Hint
Shells and plants.
Answer
(b) Limestone and coal.
Q2 · 3 marks · Short answerHarder board level
What is lithification? Explain why sedimentary rocks are layered.
Hint
Compaction, cementation, deposition in beds.
Answer
Lithification is the compaction and cementation of deposited sediments into rock. Sediments settle in successive layers, so the resulting rock is stratified.
Q3 · 4 marks · Long answerHarder board level
Name three features of metamorphic rocks and explain how heat and pressure produce each.
Hint
Hardness, bands, fossils.
Answer
They are harder and more compact than the parent rock because minerals recrystallise under pressure; they often show foliation or banding because minerals realign; and they usually lose fossils because heat and pressure destroy them.
Q4 · 4 marks · Long answerHarder board level
Explain the economic importance of sedimentary rocks, naming one Indian region.
Hint
Fuel, cement, building, water.
Answer
Coal, petroleum and gas occur in them (coal of the Damodar valley); limestone makes cement and is used in steel-making; sandstone is a building stone; porous layers hold groundwater.
Q5 · 4 marks · Case-basedHOTS / competency
A geologist finds a banded rock containing no fossils close to a mountain belt. (a) Suggest its likely group. (b) Name the process. (c) Explain why fossils are absent, and name a possible parent for a banded rock called gneiss.
Hint
Heat and pressure destroy remains.
Answer
(a) Metamorphic. (b) Regional metamorphism. (c) Heat and pressure destroy organic remains; gneiss can come from granite.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Slate comes from?Show answer
Shale.
2.Quartzite comes from?Show answer
Sandstone.
3.Where is Makrana marble?Show answer
Rajasthan.
4.Which valleys have Gondwana coal?Show answer
Damodar, Mahanadi and Godavari.
5.What drives weathering in the rock cycle?Show answer
The sun.

Sedimentary and Metamorphic Rocks and the Rock Cycle: frequently asked questions

Is coal metamorphic?

Coal is classed as an organic sedimentary rock; stronger heat and pressure can push it towards graphite.

Why are fossils rare in metamorphic rocks?

Heat and pressure usually destroy them.

Can sedimentary rock melt?

Yes, at great depth it can melt to magma, completing the cycle.