Earth Science Quiz: Rock Cycle

What this quiz covers

This quiz focuses on Rock Cycle, giving you a quick way to practice the rules, question types, and explanations that matter most for Earth Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. The geothermal gradient, which provides the heat necessary for uplift and erosion.
2. Earth's internal heat, which drives the convection that breaks the schist apart into sediment.
3. Solar energy, which drives the hydrologic cycle and climate systems responsible for weathering and transport. (correct answer)
4. Gravitational energy, which is the sole force responsible for compacting sediment into new rock.

Explanation: For a deep-seated metamorphic rock like schist to become a sedimentary rock, it must first be uplifted and exposed at the surface. Then, surface processes—weathering, erosion, and transport—must break it down and move the resulting sediment. These processes are all driven by solar energy, which powers the water cycle (rain, rivers, ice), wind, and temperature changes.

Question 2

1. Melting
2. Recrystallization
3. Uplift and Exposure (correct answer)
4. Subduction

Explanation: The diagram shows arrow 'X' representing the transformation of a metamorphic rock into a sedimentary rock. For this to happen, the metamorphic rock, which typically forms at depth, must be brought to the Earth's surface (uplift and exposure) where it can be weathered and eroded to form sediment. This sediment is then lithified into sedimentary rock. Melting would form magma. Recrystallization is part of metamorphism itself. Subduction would lead to more metamorphism or melting at depth.

Question 3

1. Melting, which is producing new magma from the granite.
2. Metamorphism, which is transforming the granite into gneiss.
3. Chemical weathering, which is breaking down the rock to form sediment. (correct answer)
4. Crystallization, which is causing the mineral grains to grow larger.

Explanation: The decomposition of feldspar into clay is a classic example of chemical weathering, a surface process. The crumbling of the rock into loose grains is physical weathering. Together, these processes break down existing rock (granite) into smaller components (quartz grains, clay minerals), which are known as sediment. This is the first step in the pathway from an igneous rock to a sedimentary rock.

Question 4

1. The geothermal gradient, which provides the heat necessary for uplift and erosion.
2. Earth's internal heat, which drives the convection that breaks the schist apart into sediment.
3. Solar energy, which drives the hydrologic cycle and climate systems responsible for weathering and transport. (correct answer)
4. Gravitational energy, which is the sole force responsible for compacting sediment into new rock.

Explanation: For a deep-seated metamorphic rock like schist to become a sedimentary rock, it must first be uplifted and exposed at the surface. Then, surface processes—weathering, erosion, and transport—must break it down and move the resulting sediment. These processes are all driven by solar energy, which powers the water cycle (rain, rivers, ice), wind, and temperature changes.

Question 5

1. The granite pluton is heated further until it melts, and the quartz crystal is incorporated into a new, higher-grade metamorphic rock upon cooling.
2. The pluton is uplifted and exposed; weathering breaks down the granite, releasing the quartz crystal. The crystal is then transported, buried, and lithified into sandstone, which is later subjected to heat and pressure. (correct answer)
3. The quartz crystal is dissolved by groundwater, transported to a basin, and then precipitated chemically to form part of a limestone deposit that is later metamorphosed.
4. The granite undergoes metamorphism directly into slate, trapping the original quartz crystal within a new foliated structure.

Explanation: This pathway correctly follows the rock cycle. 1) The igneous rock (granite) must be exposed at the surface via uplift and erosion. 2) Weathering frees the resistant quartz crystal. 3) Erosion and deposition transport the crystal to a basin where it becomes part of a sediment deposit. 4) Lithification turns the sediment into a sedimentary rock (sandstone). 5) Burial and tectonics subject the sandstone to heat and pressure, transforming it into a metamorphic rock (quartzite).

Question 6

1. The subducting materials are uplifted and exposed at the surface, where they are weathered to form new sediments on the continental plate.
2. The basalt and sediments undergo increasing heat and directed pressure, leading to metamorphism and partial melting, which generates magma for a volcanic arc. (correct answer)
3. The subducting materials are immediately and completely melted into a large magma chamber that cools slowly to form a batholith.
4. The pressure from the overriding plate compacts the materials, lithifying them into a single, uniform layer of sedimentary rock.

Explanation: In a subduction zone, the descending plate is subjected to progressively higher temperatures and pressures. This environment causes metamorphism of both the basaltic oceanic crust and the overlying sediments. The addition of water from the subducting plate lowers the melting point of the mantle wedge above it, causing partial melting. This magma then rises to form a volcanic arc on the overriding continental plate. This pathway correctly identifies metamorphism and partial melting as key processes.

Question 7

1. The sandstone must be weathered and eroded, with the resulting sediment being lithified into a new sedimentary rock before melting.
2. The sandstone must undergo intense heat and pressure, recrystallizing into gneiss, which then melts completely and cools slowly underground. (correct answer)
3. The sandstone must be heated by nearby magma, causing it to melt instantly, and then be extruded onto the surface to cool rapidly.
4. The sandstone must be compacted further and cemented with new minerals until it is hard enough to be considered an igneous rock.

Explanation: To become part of a granite pluton (an intrusive igneous rock), the sandstone must first become magma. The pathway from sedimentary to igneous rock typically involves an intermediate metamorphic stage. In a continental collision zone, the sandstone will experience intense heat and pressure (regional metamorphism), transforming it first into quartzite and then, at higher grades, potentially into gneiss. If temperatures are high enough, this metamorphic rock will melt. To form granite, a coarse-grained intrusive rock, this magma must then cool slowly deep beneath the surface.

Question 8

1. The basalt will weather more rapidly than the granite, and both will contribute to the formation of clastic sedimentary rocks. (correct answer)
2. The granite will melt more easily than the basalt, forming new magma chambers just below the surface.
3. Both rock types will weather at identical rates, producing a uniform layer of quartz-rich sand over the landscape.
4. The basalt, being denser, will undergo metamorphism due to surface pressure, while the granite will remain unchanged.

Explanation: Basalt is composed of mafic minerals (like pyroxene and olivine) that are less stable at Earth's surface conditions than the felsic minerals in granite (like quartz and feldspar). In a warm, humid climate that promotes chemical weathering, the basalt will break down more quickly. Both rocks will weather to form sediment, which can then be lithified into clastic sedimentary rocks, but their rates and product compositions will differ.

Question 9

1. Cementation by calcite is the dominant process, gluing the clay particles together, while compaction plays a minor role.
2. Heat is required to melt the edges of the clay particles, which then act as a cement during compaction.
3. Both processes are equally important; compaction reduces volume and cementation adds new mineral mass.
4. Compaction from the weight of overlying sediment is the primary process, physically squeezing water out and aligning clay minerals. (correct answer)

Explanation: When you encounter questions about sedimentary rock formation, focus on understanding how loose sediments transform into solid rock through lithification. This process involves two main mechanisms, but their relative importance varies dramatically depending on the type of sediment. For clay-to-shale transformation, compaction dominates the process. Clay particles are extremely small and flat, making them highly susceptible to pressure from overlying sediment layers. As burial depth increases, the immense weight squeezes out pore water and forces clay minerals to align parallel to each other, creating shale's characteristic layered structure. This physical reorganization is so effective that it can reduce the original sediment volume by 80% or more. Answer D correctly identifies compaction as the primary process, emphasizing how overlying weight physically expels water and reorganizes clay minerals. This mechanical process alone is sufficient to create solid shale. Answer A incorrectly suggests cementation dominates. While calcite cementation occurs in some sedimentary rocks, it's not the primary mechanism for shale formation. Answer B describes a completely fictional process—clay particles don't melt during normal sedimentary processes, which occur at surface temperatures and pressures. Answer C claims both processes are equally important, but this misrepresents the clay-to-shale transformation where compaction overwhelmingly dominates. Remember this pattern: fine-grained sediments (clay, mud) primarily undergo compaction during lithification, while coarse-grained sediments (sand, gravel) rely more heavily on cementation. The particle size determines which process dominates.

Question 10

1. It will be immediately weathered into sand and clay by chemical reactions with the lava.
2. It will melt completely due to the lava's heat, forming a new layer of intrusive igneous rock.
3. It will be compacted by the weight of the lava flows, transforming it back into a sedimentary rock.
4. It will undergo contact metamorphism from the heat of the overlying lava, potentially forming a higher-grade metamorphic rock. (correct answer)

Explanation: When you encounter rock cycle questions, focus on the specific processes that occur under different temperature and pressure conditions. This question tests your understanding of what happens when existing rocks are subjected to new thermal environments. The correct answer is D because contact metamorphism occurs when existing rocks are heated by nearby igneous activity without being buried deep enough for regional metamorphism. When hot lava flows cover the schist, the intense heat from the overlying molten rock will alter the mineral structure of the schist, potentially creating a higher-grade metamorphic rock. The schist already underwent metamorphism once, so additional heat can drive further metamorphic changes in its minerals. Let's examine why the other options are incorrect: A is wrong because weathering requires exposure to atmospheric conditions and time. Since the schist is quickly buried by lava flows, it's protected from weathering processes and won't break down into sediments. B is incorrect because while lava is extremely hot, the schist isn't in direct contact with the molten rock long enough to melt completely. Also, if it did melt, it would form igneous rock, but not intrusive igneous rock—that forms from magma cooling underground, not from surface lava flows. C misunderstands rock formation processes. Compaction alone doesn't transform metamorphic rocks into sedimentary rocks. Sedimentary rocks form from weathered materials that are deposited, compacted, and cemented—not from intact metamorphic rocks being compressed. Remember: Heat is the dominant factor in contact metamorphism, while pressure is more important in regional metamorphism. When you see scenarios involving hot igneous activity near existing rocks, think contact metamorphism.

Question 11

1. The cooling and crystallization of a basaltic lava flow on the surface.
2. The physical weathering of a limestone cliff by freeze-thaw cycles over a century.
3. The lithification of a 10-meter thick layer of sand into sandstone in a shallow marine environment.
4. The transformation of a granite into a high-grade gneiss and its subsequent uplift and exposure. (correct answer)

Explanation: When you encounter questions about geologic timescales, think about the complexity and energy requirements of each process. The rock cycle operates on vastly different timescales, from rapid surface processes to deep crustal transformations that span millions of years. Option D represents the longest timescale because it involves multiple, energy-intensive steps. First, granite must be subjected to extreme heat and pressure deep in the crust to transform into high-grade gneiss through metamorphism. This process requires temperatures of 600-800°C and pressures equivalent to burial depths of 15-25 kilometers, typically taking millions of years. Then, tectonic forces must uplift this rock and erosion must strip away overlying material to expose it at the surface—another process requiring millions of years. Option A is incorrect because basaltic lava cooling occurs rapidly, typically within days to years depending on flow thickness. The high surface temperature and direct contact with air or water accelerate heat loss and crystallization. Option B involves physical weathering over just a century—relatively instantaneous in geologic terms. Freeze-thaw cycles work quickly because water expansion during freezing creates immediate mechanical stress. Option C describes lithification, which can occur in thousands to hundreds of thousands of years in shallow marine environments where burial rates are moderate and chemical processes work relatively quickly. Remember this pattern: surface processes (cooling, weathering) happen fastest, followed by sedimentary processes (lithification), while deep crustal processes involving metamorphism and major tectonic movements require the longest timescales—often tens of millions of years.

Question 12

1. A sequence of clastic rocks like conglomerate, arkose sandstone, and shale, reflecting the mineralogy of the source. (correct answer)
2. A uniform deposit of extrusive igneous rock, as the metamorphic source rocks are re-melted during transport.
3. Mostly chemical sedimentary rocks like limestone, because the minerals in schist and gneiss dissolve easily.
4. New metamorphic rocks like quartzite and marble, as the pressure in the basin is very high.

Explanation: This question tests your understanding of the rock cycle and how metamorphic rocks weather to form sedimentary rocks. When you see questions about erosion and sediment transport, focus on what happens to the source rock's minerals during weathering and how they're deposited. When schist and gneiss erode, their component minerals (quartz, feldspar, mica, and others) break down through physical and chemical weathering. These minerals become clasts of different sizes that rivers transport and deposit in basins. Larger, more resistant fragments like quartz form coarse sediments, while smaller particles from weathered feldspars and micas create fine sediments. This size sorting during transport leads to a predictable sequence: conglomerate (coarse), arkose sandstone (medium, feldspar-rich), and shale (fine). The arkose specifically reflects the feldspar-rich mineralogy of the metamorphic source rocks. Option B is wrong because sediments don't melt during transport—they remain solid particles that undergo physical processes, not igneous processes. Option C incorrectly assumes the minerals in schist and gneiss dissolve easily, but quartz and feldspar are relatively resistant to chemical weathering compared to minerals that actually form chemical sedimentary rocks. Option D confuses the depositional environment with a metamorphic one—sedimentary basins don't have the high pressure and temperature needed to create new metamorphic rocks. Remember that the rock cycle follows predictable pathways: metamorphic rocks weather to form clastic sedimentary rocks that reflect their mineral composition, not chemical sedimentary rocks or new metamorphic rocks.

Question 13

1. The sandstone must be weathered and eroded, with the resulting sediment being lithified into a new sedimentary rock before melting.
2. The sandstone must undergo intense heat and pressure, recrystallizing into gneiss, which then melts completely and cools slowly underground. (correct answer)
3. The sandstone must be heated by nearby magma, causing it to melt instantly, and then be extruded onto the surface to cool rapidly.
4. The sandstone must be compacted further and cemented with new minerals until it is hard enough to be considered an igneous rock.

Explanation: To become part of a granite pluton (an intrusive igneous rock), the sandstone must first become magma. The pathway from sedimentary to igneous rock typically involves an intermediate metamorphic stage. In a continental collision zone, the sandstone will experience intense heat and pressure (regional metamorphism), transforming it first into quartzite and then, at higher grades, potentially into gneiss. If temperatures are high enough, this metamorphic rock will melt. To form granite, a coarse-grained intrusive rock, this magma must then cool slowly deep beneath the surface.

Question 14

1. Melting, which is producing new magma from the granite.
2. Metamorphism, which is transforming the granite into gneiss.
3. Chemical weathering, which is breaking down the rock to form sediment. (correct answer)
4. Crystallization, which is causing the mineral grains to grow larger.

Explanation: The decomposition of feldspar into clay is a classic example of chemical weathering, a surface process. The crumbling of the rock into loose grains is physical weathering. Together, these processes break down existing rock (granite) into smaller components (quartz grains, clay minerals), which are known as sediment. This is the first step in the pathway from an igneous rock to a sedimentary rock.

Question 15

1. The basalt will weather more rapidly than the granite, and both will contribute to the formation of clastic sedimentary rocks. (correct answer)
2. The granite will melt more easily than the basalt, forming new magma chambers just below the surface.
3. Both rock types will weather at identical rates, producing a uniform layer of quartz-rich sand over the landscape.
4. The basalt, being denser, will undergo metamorphism due to surface pressure, while the granite will remain unchanged.

Explanation: Basalt is composed of mafic minerals (like pyroxene and olivine) that are less stable at Earth's surface conditions than the felsic minerals in granite (like quartz and feldspar). In a warm, humid climate that promotes chemical weathering, the basalt will break down more quickly. Both rocks will weather to form sediment, which can then be lithified into clastic sedimentary rocks, but their rates and product compositions will differ.

Question 16

1. Cementation by calcite is the dominant process, gluing the clay particles together, while compaction plays a minor role.
2. Heat is required to melt the edges of the clay particles, which then act as a cement during compaction.
3. Both processes are equally important; compaction reduces volume and cementation adds new mineral mass.
4. Compaction from the weight of overlying sediment is the primary process, physically squeezing water out and aligning clay minerals. (correct answer)

Explanation: When you encounter questions about sedimentary rock formation, focus on understanding how loose sediments transform into solid rock through lithification. This process involves two main mechanisms, but their relative importance varies dramatically depending on the type of sediment. For clay-to-shale transformation, compaction dominates the process. Clay particles are extremely small and flat, making them highly susceptible to pressure from overlying sediment layers. As burial depth increases, the immense weight squeezes out pore water and forces clay minerals to align parallel to each other, creating shale's characteristic layered structure. This physical reorganization is so effective that it can reduce the original sediment volume by 80% or more. Answer D correctly identifies compaction as the primary process, emphasizing how overlying weight physically expels water and reorganizes clay minerals. This mechanical process alone is sufficient to create solid shale. Answer A incorrectly suggests cementation dominates. While calcite cementation occurs in some sedimentary rocks, it's not the primary mechanism for shale formation. Answer B describes a completely fictional process—clay particles don't melt during normal sedimentary processes, which occur at surface temperatures and pressures. Answer C claims both processes are equally important, but this misrepresents the clay-to-shale transformation where compaction overwhelmingly dominates. Remember this pattern: fine-grained sediments (clay, mud) primarily undergo compaction during lithification, while coarse-grained sediments (sand, gravel) rely more heavily on cementation. The particle size determines which process dominates.

Question 17

1. It will be immediately weathered into sand and clay by chemical reactions with the lava.
2. It will melt completely due to the lava's heat, forming a new layer of intrusive igneous rock.
3. It will be compacted by the weight of the lava flows, transforming it back into a sedimentary rock.
4. It will undergo contact metamorphism from the heat of the overlying lava, potentially forming a higher-grade metamorphic rock. (correct answer)

Explanation: When you encounter rock cycle questions, focus on the specific processes that occur under different temperature and pressure conditions. This question tests your understanding of what happens when existing rocks are subjected to new thermal environments. The correct answer is D because contact metamorphism occurs when existing rocks are heated by nearby igneous activity without being buried deep enough for regional metamorphism. When hot lava flows cover the schist, the intense heat from the overlying molten rock will alter the mineral structure of the schist, potentially creating a higher-grade metamorphic rock. The schist already underwent metamorphism once, so additional heat can drive further metamorphic changes in its minerals. Let's examine why the other options are incorrect: A is wrong because weathering requires exposure to atmospheric conditions and time. Since the schist is quickly buried by lava flows, it's protected from weathering processes and won't break down into sediments. B is incorrect because while lava is extremely hot, the schist isn't in direct contact with the molten rock long enough to melt completely. Also, if it did melt, it would form igneous rock, but not intrusive igneous rock—that forms from magma cooling underground, not from surface lava flows. C misunderstands rock formation processes. Compaction alone doesn't transform metamorphic rocks into sedimentary rocks. Sedimentary rocks form from weathered materials that are deposited, compacted, and cemented—not from intact metamorphic rocks being compressed. Remember: Heat is the dominant factor in contact metamorphism, while pressure is more important in regional metamorphism. When you see scenarios involving hot igneous activity near existing rocks, think contact metamorphism.

Question 18

1. Shale, a sedimentary rock, is buried and metamorphosed into slate.
2. Sandstone, a sedimentary rock, is uplifted and weathers into sand, which forms new sandstone. (correct answer)
3. Gneiss, a metamorphic rock, melts to form magma that crystallizes into granite.
4. Basalt, an igneous rock, is weathered into sediment that forms a clastic sedimentary rock.

Explanation: This example illustrates a 'shortcut' where a rock type transforms back into itself without passing through other stages. A sedimentary rock (sandstone) being weathered to produce sediment that then forms another sedimentary rock demonstrates that the cycle is not a rigid, one-way path. The other options describe pathways that are part of the simple, sequential cycle and do not refute it.

Question 19

1. The granite pluton is heated further until it melts, and the quartz crystal is incorporated into a new, higher-grade metamorphic rock upon cooling.
2. The pluton is uplifted and exposed; weathering breaks down the granite, releasing the quartz crystal. The crystal is then transported, buried, and lithified into sandstone, which is later subjected to heat and pressure. (correct answer)
3. The quartz crystal is dissolved by groundwater, transported to a basin, and then precipitated chemically to form part of a limestone deposit that is later metamorphosed.
4. The granite undergoes metamorphism directly into slate, trapping the original quartz crystal within a new foliated structure.

Explanation: This pathway correctly follows the rock cycle. 1) The igneous rock (granite) must be exposed at the surface via uplift and erosion. 2) Weathering frees the resistant quartz crystal. 3) Erosion and deposition transport the crystal to a basin where it becomes part of a sediment deposit. 4) Lithification turns the sediment into a sedimentary rock (sandstone). 5) Burial and tectonics subject the sandstone to heat and pressure, transforming it into a metamorphic rock (quartzite).

Question 20

1. A sequence of clastic rocks like conglomerate, arkose sandstone, and shale, reflecting the mineralogy of the source. (correct answer)
2. A uniform deposit of extrusive igneous rock, as the metamorphic source rocks are re-melted during transport.
3. Mostly chemical sedimentary rocks like limestone, because the minerals in schist and gneiss dissolve easily.
4. New metamorphic rocks like quartzite and marble, as the pressure in the basin is very high.

Explanation: This question tests your understanding of the rock cycle and how metamorphic rocks weather to form sedimentary rocks. When you see questions about erosion and sediment transport, focus on what happens to the source rock's minerals during weathering and how they're deposited. When schist and gneiss erode, their component minerals (quartz, feldspar, mica, and others) break down through physical and chemical weathering. These minerals become clasts of different sizes that rivers transport and deposit in basins. Larger, more resistant fragments like quartz form coarse sediments, while smaller particles from weathered feldspars and micas create fine sediments. This size sorting during transport leads to a predictable sequence: conglomerate (coarse), arkose sandstone (medium, feldspar-rich), and shale (fine). The arkose specifically reflects the feldspar-rich mineralogy of the metamorphic source rocks. Option B is wrong because sediments don't melt during transport—they remain solid particles that undergo physical processes, not igneous processes. Option C incorrectly assumes the minerals in schist and gneiss dissolve easily, but quartz and feldspar are relatively resistant to chemical weathering compared to minerals that actually form chemical sedimentary rocks. Option D confuses the depositional environment with a metamorphic one—sedimentary basins don't have the high pressure and temperature needed to create new metamorphic rocks. Remember that the rock cycle follows predictable pathways: metamorphic rocks weather to form clastic sedimentary rocks that reflect their mineral composition, not chemical sedimentary rocks or new metamorphic rocks.