Igneous Rocks
100 — What is the name for igneous rock that forms when magma cools slowly beneath Earth's surface, usually producing large crystals?
100 — Intrusive igneous rock (example: granite)
100 — What process turns loose sediment into sedimentary rock by pressing layers together?
. 100 — Compaction (and cementation)
100 — What is the name of the process by which existing rock changes into metamorphic rock due to heat and pressure (without melting)?
Metamorphism
100 — What term describes the overall set of processes that change rocks from one type to another?
The rock cycle
100 — What is a mineral?
Mineral: naturally occurring, usually inorganic solid with definite chemical composition and orderly internal structure
200 — What do we call igneous rock that forms when lava cools quickly at Earth's surface and often has very small crystals?
200 — Extrusive igneous rock (fine-grained; example: basalt, obsidian is glassy)
200 — Name one way minerals can be added to forming sedimentary rock (a process involving water)
200 — Dissolved minerals in water can cement sediments (minerals crystallize as water moves/evaporates)
200 — Typical temperature ranges for metamorphism. Give the approximate range in degrees Celsius.
About 200∘C to 1,200∘C
200 — Name two processes that can change sedimentary rock into other rock types
Examples: burial + pressure/temperature → metamorphism; melting and cooling → igneous rock; weathering → sediment → sedimentary rock
200 — What is a crystal (in relation to minerals)?
A crystal is a solid with atoms/molecules arranged in a repeating pattern; crystal size depends on formation conditions
300 — Explain why two igneous rocks with the same chemical composition might look different. (Give the key factor.)
300 — Cooling rate: slow cooling → larger crystals; fast cooling → small or no crystals
300 — Which type of sedimentary rock can form from the remains of once-living plants and animals?
300 — Coal (from plant material) or limestone from marine organisms
Why might a metamorphic rock like gneiss show alternating light and dark bands? (Brief explanation)
Recrystallization and segregation of minerals under pressure and temperature produces banding (light/dark mineral bands)
300 — Describe two possible pathways igneous rock can take to become a different rock type (include at least one direct change and one involving melting).
300 — Igneous → metamorphic directly (via pressure/temperature); igneous → melt to magma → cool to new igneous rock
300 — List three different natural processes that can form minerals
Cooling of melted rock; changing heat and pressure; evaporation of mineral-rich water (leaving minerals behind)
400 — Name two common extrusive igneous rocks
400 — Basalt and andesite (text mentions basalt and andesite; obsidian as glassy example)
400 — Explain why sedimentary rocks often show visible layers and how those layers might become exposed at the surface.
400 — Layers form as sediment is deposited over time; uplift and erosion expose layers (e.g., Grand Canyon)
400 — Explain two different ways metamorphic rock can form (one near magma, one from burial).
Contact metamorphism (near magma chamber heat) and regional metamorphism (burial and pressure over large areas)
400 — Explain how weathering contributes to the rock cycle — include what it produces and one rock type that can form from that material
400 — Weathering breaks rocks into sediment; sediments can form sedimentary rock via deposition/compaction/cementation; igneous or metamorphic rocks can be weathered to form sediments
400 — Explain how the appearance of a rock can give clues about how it formed (mention at least one connection between appearance and formation conditions).
Example: large visible crystals indicate slow cooling below surface (intrusive); fine-grained or glassy texture indicates rapid cooling at surface (extrusive); layering suggests deposition over time (sedimentary); banding indicates metamorphism
500 — Describe how uplift can make intrusive igneous rock visible at Earth's surface and name one large mountain range made mostly of intrusive rock
500 — Uplift pushes intrusive rock toward surface; example: the Rockies (granite)
Describe three events (in order) that could lead to the formation of a Valley as given in the text (short sequence).
(One acceptable short sequence) deposition of sediments near sea level → burial and compaction/cementation into sedimentary rock → uplift to high elevation → erosion and river action remove rock to form current landscape
500 — Describe how metamorphic rock could end up exposed at Earth's surface so that we can observe it
500 — Uplift and erosion remove overlying rock, exposing deep-formed metamorphic rock at the surface
Draw (describe in words) a simple rock-cycle pathway that shows limestone changing into sediment and also limestone changing into marble. (List the processes for each change.)
500 — Limestone → sediment: weathering and erosion break limestone into sediment (deposition of those sediments forms new sedimentary rock). Limestone → marble: burial + pressure and temperature (metamorphism) recrystallizes limestone into marble.
500 — When rock melts and becomes magma, what eventually must happen for it to become igneous rock again? Include what happens to crystals when cooling is slow vs. fast.
Magma must cool and solidify to form igneous rock; slow cooling allows larger crystals to grow, fast cooling yields smaller crystals or none (glassy)