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36 Geology Trivia Questions for Kids

The easiest geology questions in the game, picked for younger players. Every one comes with the answer and a short explanation of why it is right.

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Easy Geology Questions and Answers

  1. What cave formation grows upward from the floor?

    Stalagmite

    It forms as mineral-laden water drips from the cave roof and deposits calcite on the floor below, building upward layer by layer. Growth is so slow that many stalagmites take thousands of years to reach just a few centimeters tall.

    Easy · Also offered: Cave pearl, Soda straw, Cave popcorn · Source: NPS

  2. Which two metals make up most of Earth's core?

    Iron and nickel

    Earth's core is composed primarily of iron and nickel, unlike the rocky silicate materials that dominate the mantle and crust.

    Easy · Also offered: Copper and zinc, Aluminum and silicon, Calcium and sodium · Source: U.S. Geological Survey, The Interior of the Earth

  3. Which layer of Earth stays solid even though it is the hottest part of the planet?

    Inner core

    Pressure at Earth's center is so extreme, several million times that at the surface, that it keeps iron and nickel locked into a solid even though the temperature there rivals the surface of the Sun.

    Easy · Also offered: Outer core, Asthenosphere, Crust · Source: NASA Science

  4. Which major compositional layer of Earth is thinnest?

    Crust

    The crust is a thin rocky shell compared with the mantle and core.

    Easy · Also offered: Mantle, Outer core, Inner core · Source: USGS, Interior of Earth

  5. What surface location lies directly above an earthquake's focus?

    Epicenter

    The epicenter is the point on Earth's surface above the focus.

    Easy · Also offered: Hypocenter, Fault scarp, Seismic station · Source: USGS, The Science of Earthquakes

  6. What directly causes the shaking of an earthquake?

    A sudden slip on a fault

    An earthquake occurs when stress overcomes friction on a fault and the rocks suddenly slip, releasing energy as seismic waves.

    Easy · Also offered: Magma rising beneath a volcano, A landslide on a steep slope, Rock slowly bending without breaking · Source: U.S. Geological Survey, How the Earth Moves

  7. What geological process carries weathered rock and sediment from one place to another?

    Erosion

    Erosion transports weathered rock and sediment from one place to another, often through water, wind, ice, or gravity. Over time, it can carve valleys and reshape coastlines.

    Easy · Also offered: Weathering, Deposition, Lithification · Source: USGS

  8. The word 'volcano' comes from Vulcan, the Roman god of what?

    Fire and the forge

    Vulcan was the Roman god of fire and metalworking. The Aeolian island of Vulcano, thought to sit above his forge, passed its name on to every mountain that erupts.

    Easy · Also offered: Earthquakes and landslides, Mountains and high places, Thunder and lightning · Source: Oxford English Dictionary, 'volcano'

  9. What waterway chiefly carved the Grand Canyon?

    Colorado River

    The Colorado River is chiefly responsible for carving the Grand Canyon.

    Easy · Also offered: Mississippi River, Rio Grande, Columbia River · Source: National Park Service, Grand Canyon Geology

  10. A preserved footprint is classified as what?

    Trace fossil

    A preserved footprint records an organism's activity, making it a trace fossil. The alternatives are genuine fossil categories.

    Easy · Also offered: Body fossil, Mold fossil, Cast fossil · Source: National Park Service, Trace Fossils

  11. In which type of material are fossils most often found?

    Sedimentary rock

    Fossils form most often in sedimentary rock, because mud, sand and silt settle gently over remains and bury them before they rot away. Rock made by heat or crushing pressure destroys whatever structure was there.

    Easy · Also offered: Igneous rock, Metamorphic rock, Glacial ice · Source: U.S. Geological Survey, Find-A-Feature: Fossil

  12. What process widens cracks when water freezes and expands?

    Frost wedging

    Water expands by about 9 percent as it freezes, and the resulting pressure is enough to pry rock apart along existing cracks. It does most of its damage in climates where the temperature crosses freezing point repeatedly, such as alpine and subpolar regions, rather than in places that are simply cold.

    Easy · Also offered: Salt crystallisation, Exfoliation, Root wedging · Source: National Park Service, Rockfall in Zion National Park

  13. Which common building stone is a coarse-grained igneous rock?

    Granite

    Granite forms as magma cools slowly deep underground, which gives the crystals time to grow large. That is why a polished slab shows visible interlocking grains of quartz, feldspar and mica.

    Easy · Also offered: Slate, Sandstone, Marble · Source: USGS

  14. Which rock can form when limestone is changed by heat and pressure?

    Marble

    Heat and pressure can metamorphose limestone into marble, changing its texture and mineral structure without melting it completely.

    Easy · Also offered: Granite, Basalt, Sandstone · Source: National Geographic Society, The Rock Cycle

  15. Where is new oceanic crust most commonly created?

    At a mid-ocean ridge

    New oceanic crust forms most commonly at mid-ocean ridges, where tectonic plates diverge and magma cools. The alternatives are real oceanic tectonic settings but are less common or do not typically produce new crust.

    Easy · Also offered: At a trench, At a mantle plume, At a back-arc basin · Source: NOAA Ocean Exploration, Mid-Ocean Ridge

  16. What is a mineral's tendency to split along flat planes called?

    Cleavage

    Cleavage reflects weaknesses in a crystal lattice.

    Easy · Also offered: Luster, Streak, Density · Source: National Park Service, Minerals

  17. What ranks minerals by resistance to scratching?

    Mohs scale

    The Mohs scale ranks minerals by their resistance to scratching. It ranges from talc at 1 to diamond at 10, though the scale is relative rather than evenly spaced.

    Easy · Also offered: Vickers scale, Brinell scale, Rockwell scale · Source: USGS

  18. Which mineral is the softest standard on the Mohs scale?

    Talc

    Talc has Mohs hardness 1.

    Easy · Also offered: Gypsum, Quartz, Feldspar · Source: National Park Service, Mohs Hardness Scale

  19. What is molten rock called after it reaches Earth's surface?

    Lava

    Molten rock beneath Earth's surface is magma; once it erupts onto the surface, it is called lava.

    Easy · Also offered: Magma, Basalt, Tephra · Source: U.S. Geological Survey, This Dynamic Earth

  20. What type of rock is obsidian?

    Volcanic glass

    Obsidian is volcanic glass formed when viscous magma erupts as lava and cools rapidly, preventing crystals from forming.

    Easy · Also offered: Basalt, Flint, Anthracite coal · Source: U.S. Geological Survey, Yellowstone's Tool-Making Lava Flows

  21. What is a natural concentration of minerals valuable enough to extract called?

    Ore

    Ore contains economically recoverable minerals or metals.

    Easy · Also offered: Moraine, Regolith, Fossil · Source: USGS, EarthWord: Ore

  22. What was the ancient supercontinent called before today's continents separated?

    Pangaea

    Pangaea was a single ancient supercontinent that gradually broke apart as the continents moved into their present positions.

    Easy · Also offered: Gondwana, Laurasia, Rodinia · Source: U.S. Geological Survey, What was Pangea?

  23. New seafloor is created along mid-ocean ridges. Which kind of plate boundary makes it?

    Divergent boundary

    A divergent boundary forms where tectonic plates move away from each other. As they separate, magma rises to fill the gap and can create new crust, especially along underwater mid-ocean ridges.

    Easy · Also offered: Convergent boundary, Transform boundary, Subduction boundary · Source: U.S. Geological Survey, This Dynamic Earth

  24. At a convergent boundary between oceanic and continental crust, what happens?

    The oceanic plate subducts

    Oceanic crust is denser than continental crust, mostly basalt rather than granite, so it dives into the mantle instead of crumpling upward. This is the mechanism that built the Andes and carved deep trenches like the one off the coast of Chile.

    Easy · Also offered: The continental plate subducts, A mid-ocean ridge opens between them, The plates grind past each other sideways · Source: USGS, This Dynamic Earth

  25. At what kind of tectonic setting do plates mainly slide horizontally past one another?

    Transform boundary

    At a transform boundary, tectonic plates slide horizontally past one another. This motion often produces earthquakes, such as those along California’s San Andreas Fault.

    Easy · Also offered: Divergent boundary, Convergent boundary, Plate boundary zone · Source: USGS, This Dynamic Earth

  26. What makes pumice buoyant?

    Trapped gas bubbles

    Pumice can float because trapped, isolated gas bubbles make it less dense than water. If water eventually fills those tiny pockets, the pumice sinks.

    Easy · Also offered: High silica content, Rapid lava cooling, Abundant crystal growth · Source: U.S. Geological Survey, Volcano Watch

  27. What landform can build up where a river drops its sediment at the mouth?

    Delta

    Where a river meets the sea or a lake it slows suddenly and can no longer carry its load, so sand and silt settle out and the channel splits into branches picking their way across the deposit. The fan of land that results is a delta, named after the Greek letter for the triangular shape of the Nile's.

    Easy · Also offered: Canyon, Moraine, Volcanic cone · Source: USGS

  28. Which sedimentary rock forms when grains between about 0.06 and 2 mm across are cemented together?

    Sandstone

    Sand grains can accumulate, compact, and become cemented into sandstone; gravel forms conglomerate and mud can form shale.

    Easy · Also offered: Conglomerate, Shale, Marble · Source: U.S. Geological Survey, Fossils, Rocks, and Time: Rocks and Layers

  29. Which seismic disturbance travels fastest?

    P wave

    P waves travel fastest because they move through the Earth by compressing and expanding material in the direction of travel. They can pass through solids and liquids, unlike S waves, which cannot travel through liquids.

    Easy · Also offered: S wave, Stoneley wave, Scholte wave · Source: USGS, The Science of Earthquakes

  30. Which agent typically carves broad U-shaped valleys?

    Glaciers

    Moving glaciers can scour valley sides and floors into broad U-shaped profiles as they erode the landscape.

    Easy · Also offered: Rivers, Wind, Lava flows · Source: U.S. National Park Service, U-Shaped Valleys

  31. Volcanic ash is made mostly of what?

    Tiny fragments of rock, mineral and glass

    Volcanic ash is pulverised rock: fragments of rock, mineral crystals and volcanic glass under 2 millimetres across, thrown out when an eruption shatters magma. It is hard, abrasive and does not dissolve in water, which is why it ruins jet engines and collapses roofs.

    Easy · Also offered: Tiny particles of soot from burning vegetation, Tiny droplets of condensed sulfuric acid, Tiny crystals of frozen water · Source: USGS, Volcanic Ash Particle Size

  32. A volcano's conduit ends at the surface in which feature?

    Vent

    A vent is the opening at the surface where lava, ash and gas escape. A volcano usually has a central vent at the summit, and can open smaller flank vents on its sides.

    Easy · Also offered: Caldera, Batholith, Dike · Source: USGS

  33. What type of volcano has broad, relatively gentle slopes?

    Shield volcano

    Shield volcanoes are built by runny basaltic lava that travels a long way before it cools, spreading into a low, wide dome rather than a cone. Mauna Loa in Hawaii is the classic example.

    Easy · Also offered: Cinder cone, Stratovolcano, Lava dome · Source: USGS, Principal Types of Volcanoes

  34. Mount Fuji, Vesuvius and Mount St Helens are all steep cones built from alternating lava and tephra. What type of volcano is that?

    Stratovolcano

    A stratovolcano, also called a composite volcano, is built up from alternating layers of lava flows and tephra, the ash and fragments an eruption throws out. The mix stacks into the steep classic cone of Fuji, Vesuvius and Mount St Helens.

    Easy · Also offered: Shield volcano, Cinder cone, Lava dome · Source: USGS, Principal Types of Volcanoes

  35. What is the breakdown of rock at Earth's surface without transport called?

    Weathering

    Weathering breaks rock down in place; erosion moves the products.

    Easy · Also offered: Erosion, Deposition, Subduction · Source: USGS, Weathering and Erosion

  36. Which diamond is the largest gem-quality rough diamond ever found, at 3,106 carats?

    The Cullinan Diamond

    A mine surface manager found the stone at the Premier mine in South Africa in January 1905 and was given a bonus for the discovery. It was later cut into nine major stones, including the pear-shaped Cullinan I, or Great Star of Africa, which is now set in the British Sovereign's Sceptre.

    Easy · Also offered: The Lesedi La Rona, The Golden Jubilee Diamond, The Excelsior Diamond · Source: Wikipedia, Cullinan Diamond

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