The Rock Cycle
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40 free The Rock Cycle trivia questions with answers — science & nature quiz, new questions added Oct 2026.
Every rock on Earth is on a journey. Molten material cools into igneous rock, wind and water wear it down into sediment, burial presses that sediment into sedimentary rock, and heat and pressure deep underground reshape it into metamorphic rock, which may melt and start the whole loop again. Nothing is ever finished; it is only passing through. This quiz covers the rock cycle the way a high school earth science class does: the three rock families and how each one forms, the processes that move material between them, the well-known rocks worth recognising by name, and the landscapes and thinkers that revealed how slowly the planet recycles itself. The metamorphic stage gets plenty of attention, since it is the part most students find hardest. It suits students revising for a test, teachers who want a ready-made review round for the board, and anyone curious about what the ground beneath them used to be. Every answer comes with a short explanation, so you can play it straight through or print it for class.
30 of 40 questions with answers and explanations. Play the quiz
Q 01Seabed limestone now caps Mount Everest thanks to which rock-cycle process, driven by colliding continents?
Uplift
Uplift has carried rock laid down in a shallow sea to the roof of the world: the limestone at Everest's summit still holds broken trilobites and sea lilies.
Q 02Which fine-grained volcanic rock makes up both Earth's ocean floor and the dark 'seas' on the Moon?
Basalt
Basalt accounts for more than 90 percent of all volcanic rock on Earth, and the Moon's dark patches are plains of it that flooded ancient impact basins.
Q 03The giant moai statues of Easter Island were mostly carved from which soft rock made of volcanic ash?
Tuff
Tuff, volcanic ash compressed into soft stone, was used for all but 53 of the 900-plus moai. Nearly 400 statues in various stages of completion still lie at the Rano Raraku quarry.
Q 04Which glassy volcanic rock, formed when lava cools too fast for crystals to grow, was chipped into razor-sharp blades?
Obsidian
Obsidian breaks into edges so sharp that it has been tried out as surgical scalpel blades. Neolithic craftsmen traded their bladelets across southern Europe.
Q 05Limestone that is heated and squeezed deep underground recrystallises into which rock, used to build the Taj Mahal?
Marble
Marble lets light sink a little way into the stone before scattering back out, which gives statues carved from it a lifelike, waxy glow.
Q 06Lava that erupts underwater cools into rounded lumps that geologists name after which bedroom item?
Pillows
Pillows of lava pile up wherever an eruption happens underwater, and thick stacks of them form the upper layer of the crust beneath the oceans.
Q 07Which energy source powers the rain and rivers that wear rock down and carry sediment to the sea?
The Sun
The Sun lifts water from the oceans by evaporation, so every raindrop and river that carves rock runs on solar energy. Heat from inside Earth powers the melting side of the rock cycle.
Q 08Which black sedimentary rock began as swamp plants that were buried, squeezed and heated over millions of years?
Coal
Coal is mostly a relic of two geological periods: about 90 percent of all coal beds were laid down in the Carboniferous and Permian, when wetland forests covered the tropics.
Q 09Heat and pressure usually destroy which prized finds, making sedimentary rock the best place to hunt?
Fossils
Fossils survive in sedimentary rock because it forms at temperatures and pressures gentle enough to spare them, which is why its layers are the main record of the history of life.
Q 10Which hard, speckled rock, formed from magma that cooled slowly underground, makes up Yosemite's El Capitan?
Granite
Granite forms the sheer face of El Capitan, a pale monolith about 3,000 feet from base to summit that solidified roughly 100 million years ago.
Q 11Erratics, boulders stranded far from any matching bedrock, were carried there by which agent of erosion?
Glaciers
Glaciers can haul boulders for hundreds of kilometres before melting away and dropping them; Big Rock in Alberta, at 16,500 tonnes, arrived that way.
Q 12Rock in high mountains is pried apart mainly by which substance growing inside the cracks?
Ice
Ice growing in a crack forces the walls a little further apart with each freeze; geologists rank this frost action as the most important physical way rock breaks down.
Q 13Which soft white rock, built from the shells of microscopic sea plankton, forms the White Cliffs of Dover?
Chalk
Chalk is a limestone made almost entirely of the tiny calcite shells of plankton that sank to the sea floor; matching cliffs face Dover at Cap Blanc-Nez in France.
Q 21Which term for igneous rocks formed deep underground comes from the Roman god of the underworld?
Plutonic
Plutonic rocks cool slowly far below the surface and grow coarse crystals, while volcanic rocks take their name from another Roman god, Vulcan.
Q 22Rainwater absorbs a gas from the air to become which kind of weak acid, the one that hollows limestone into caves?
Carbonic
Carbonic acid forms when rain absorbs carbon dioxide; feeble as it is, it seeps down fissures and dissolves limestone into caverns and sinkholes.
Q 23Sedimentary rock is laid down in visible layers that geologists call by which Latin name?
Strata
Strata is the plural of stratum, and reading the order of these layers is the main way geologists have pieced together the history of Earth.
Q 14Which landmark, carved by the Colorado River, exposes nearly two billion years of stacked rock layers?
Grand Canyon
The Grand Canyon's walls step down from 270-million-year-old limestone at the rim to rock about two billion years old in the Inner Gorge.
Q 15Which landform builds up where a river slows and drops sediment, as at the mouths of the Nile and Mississippi?
Delta
A delta takes its name from the Nile's mouth, whose triangular outline matches the Greek capital letter; Herodotus noted that Ionian Greeks already called it the Delta.
Q 16Which cave formations hang from limestone ceilings like stone daggers, built up by dripping mineral-rich water?
Stalactites
Stalactites grow as each drip leaves a trace of calcium carbonate behind, and even the fastest lengthen by only about 3 mm a year.
Q 17About two-thirds of the world's volcanoes, active or dormant, stand in a belt around the rim of which ocean?
Pacific
The Pacific is ringed by places where ocean floor sinks back into the mantle, a belt that also produces about 90 percent of the world's earthquakes.
Q 18Shale squeezed by gentle metamorphism becomes which fine-grained rock, long split into roof tiles and blackboards?
Slate
Slate splits into smooth, flat sheets, which is why it has also long been used as the bed beneath the cloth of billiard tables.
Q 19Which frothy volcanic rock is light enough to float, sometimes drifting across oceans in vast rafts?
Pumice
Pumice can be up to 85 percent empty space, and after Krakatoa exploded, rafts of it drifted through the Indian Ocean for up to 20 years.
Q 20Which rock-cycle process breaks rock down where it sits, unlike erosion, which carries the pieces away?
Weathering
Weathering attacks rock in place through water, air and living things; erosion only begins once wind, water or gravity move the pieces.
Q 24Which process drags old ocean floor back down into the mantle at deep-sea trenches, recycling rock?
Subduction
Subduction happens because old, cold ocean floor is slightly denser than the hot mantle layer beneath it, so the slab sinks under its own weight.
Q 25Which process, named from the Greek for rock, squeezes and glues loose sediment into solid stone?
Lithification
Lithification destroys the pore space in sediment: burial packs the grains together and squeezes out trapped water, then dissolved minerals cement them.
Q 26Which Scottish farmer and physician, called the father of modern geology, argued that rock is endlessly remade?
James Hutton
James Hutton spent some 25 years on his Theory of the Earth, read to the Royal Society of Edinburgh in 1785, which pictured a planet recycling its rocks over immense time.
Q 27Sandstone fused by heat and pressure becomes which very hard metamorphic rock, often crushed for highway building?
Quartzite
Quartzite is an interlocking mosaic of crystals so tough that people have shaped it into stone tools since prehistoric times.
Q 28New seafloor crust is created as magma rises where plates pull apart, along which undersea features?
Mid-ocean ridges
Mid-ocean ridges link up into the longest mountain range in the world, a 65,000 km chain that runs through every ocean and dwarfs the Andes.
Q 29Which flaky, mica-rich metamorphic rock takes its name from a Greek word meaning 'to split'?
Schist
Schist splits easily into flakes along its layers of glittering mica; one variety, Manhattan schist, is part of the bedrock that anchors New York's skyscrapers.
Q 30Which type of metamorphism bakes the rock immediately around a body of hot magma, forming a halo called an aureole?
Contact
Contact metamorphism is driven by heat rather than pressure, and the baked zone can reach several kilometres wide around the largest magma bodies.