Rocks Flashcards
Rock definition
solid mass of a mineral or mineral-like substance that occurs naturally
Most rocks occur as ___ of different ___ in a way where …
aggregates
minerals
each mineral’s individual properties are retained
Can a rock be made of an entire mineral? Give an example
yes, limestone made up of calcite (mineral)
3 Examples of rocks made of non-mineral matter (mineral-like)
obsidian and pumice (volcanic rocks) and coal
What does the rock cycle prove?
any rock can be transformed to another rock under the right condition
How does the rock cycle begin?
melting of the crust and mantle creates magma, which rises since it’s less dense
In the rock cycle, what does the magma produce, how, and at what surfaces?
erupts at the surface (lava) and undergoes cooling (solidification/crystallization) or magma (in crust) solidifies beneath the surface and forms igneous rocks
Name the types of igneous rocks formed based on the location of formation
At surface: extrusive/volcanic igneous rocks
Beneath surface: intrusive/plutonic igneous rocks
TF: many oceanic islands are volcanic
where are extrusive igneous rocks found?
true
northwest
How are intrusive igneous rocks exposed to the surface? Ex. then what happens
uplift and erosion
mt rushmore + Yosemite
What occurs when igneous rocks are exposed to the surface? What does it cause in the next step of the rock cycle?
get weathered, loose material moved downslope by gravity and is transported by erosional agents and deposited as sediment
What is the next step after sediment deposition in the rock cycle?
lithification to sedimentary rock via compaction (forced closer tog.) or cementation (groundwater fills voids with mineral matter to make them stick to each other)
Where are most sediments transported?
oceans
What is the next step in the rock cycle after sedimentary rock forms
gets buried deep in the crust or is involved in mt-building, heat and pressure converts it to metamorphic rock
What happens when metamorphic rock is subjected to higher temps?
Creates magma, process repeats
What are the 5 alternative pathways for rocks? What three categories can we break them down into?
uplifted, weathered, transported, and deposited as sediment
- metamorphic
- sedimentary
intrusive igneous exposed to high temp, pressure, & mt-building/metamorphize
3. intrusive igneous
4. metamorphic
- intrusive igneous exposed to high temp–> melt to magma
What kind of processes produce igneous rocks? Sedimentary? Metamorphic?
internal
external
internal
What kind of minerals is magma composed of? gases? solids?
silicate minerals: 0xygen & Si
water vapor
mineral crystals
crystallization process of magma
ions arrange themselves in orderly patterns, small crystals formed, ions added to center of growth, growth stops when crystal edges meet
Slow cooling of magma - crystal
Fast cooling of magma - crystal
instant cooling
slow: fewer. larger
fast: many, tiny inter grown
randomly distributed atoms produce volcanic rocks called glass
What else influences crystallization
comp of magma and amount of dissolved gases
slow cooling is common where?
magma chambers deep in crust
