Quiz 3 Flash Cards
Plates “converge”; come together. If the two plates are of equal density, they will push up against each other. If not, they will sink.
Convergent plate boundary
Atoms arranged in regular, repeating structures.
Crystalline
Less dense, plastic (can change shape/flow under stress), plastic part contains small % of molten rock.
Upper mantle
Fine-grained, breaks along parallel lines, completely altered from preexisting rocks.
Schist
A segment of the lithosphere; the fractured surface.
Lithospheric plates
These plates move in response to the plastic flow in the hot asthenosphere.
Lithospheric/tectonic plates
Contact plane between Earth’s crust and the mantle below it; density discontinuity.
Moho
Composed primarily of minerals, though can also contain other materials such as coal or volcanic glass.
Rocks
[Type of igneous rock- Intrusive vs. Extrusive]
If it penetrates all the way to the surface and spills out as lava or ash.
Extrusive igneous rocks
Form from chemical solution or from organic deposition
Nonclastic
A boundary along which two plates are sliding past each other.
Transform plate boundary
A magma pipe led to a chamber that grew, dome-like, pushing the overlying strata into a gentle bulge without destroying them.
Laccolith
The layering of sedimentary rocks.
Stratification
[Type of igneous rock- Intrusive vs. Extrusive]
If upward thrust ceases before it reaches the surface.
Intrusive igneous rocks
Rock formation; the process of compression, compaction, and cementation whereby a sediment is transformed into a sedimentary rock.
Lithification
The creation of new lithospheric material and its continuous movement away from its source.
Seafloor spreading
Has silica 3D structure, but contains aluminum and other elements. Less resistant to weathering than quartz.
Feldspars
Simple structure, 3D framework containing only silicon and oxygen.
Quartz
Often occurs within larger horizontal strata; sedimentary rocks are layered.
Cross-bedding
Upper mantle below lithosphere; hot rock is plastic.
Asthenosphere
Volcanic island chain formed where two oceanic plates are converging. One plate will subduct the other; form deep trenches.
Island arc
Outer layers/shells peel away, leaving the lower layers exposed. Caused by the release of confining pressure.
Exfoliation
Massive body of intrusive rock that has melted and assimilated many of the existing rock structures it has invaded.
Batholith
Liquid, less pressure, melting-pint temp lower.
Outer core
Banded appearance of certain metamorphic rocks; bands formed by minerals realigned into parallel strips during metamorphism.
Foliation
Grains are sand-sized; often are quartz grains.
Sandstone
Metamorphic rock from sandstone; hard rock, resists weathering.
Quartzite
Can form from accumulation of marine shell fragments on a beach or on the ocean floor; or can form from the respiration and photosynthesis of marine organisms in which calcium carbonate is crystalized from seawater.
Finely textured, resistant to erosion.
Limestone
Similar to the batholith, but smaller.
Stock
Naturally occurring inorganic element or compound having a definite chemical composition, physical properties, and crystalline structure.
Mineral
Sedimentary rocks made from particles of other rocks
Clastic
A composite rock made of gravels, pebbles, and sometimes even boulders. Coarsest grained sedimentary rock.
Conglomerate
Large, stable, flat expanses of cold metamorphic and igneous rocks.
Continental shields
Contain silicon and oxygen; crust made up of 75% of it.
Silicate minerals
Finest grained clastic sedimentary rock type. Compacted mud, made from tiny clay particles.
Shale
Pulses of energy generated by earthquakes that can pass through the entire Earth.
Seismic waves
A long, steep valley formed when two parallel rifts form in the Earth’s crust and the land between them sinks.
Rift valley
Magma that cuts vertically across existing layers and forms a barrier wall.
Dike
Magma wells up; pushes/”diverges”/spreads the plates away, forms rift valley.
Divergent plate boundary
Vertical difference between the highest and lowest elevations in a given area.
Relief – Mountains are high relief, plains are low relief.
Less dense continental plate overrides denser oceanic plate, forces it downward.
Subduction
Light-colored, coarse-grained, formed as a felsic intrusive rock.
Granite
Rock: High-density, dark-colored, lower content of silica (ex: basalt)
Mafic rocks
Contains basic building block of one carbon and three oxygens.
Carbonate minerals
Rock: low-density, silica, light-colored (ex: granite)
Felsic rocks
The tendency of rocks to develop parallel sets of fractures without any obvious movement along the plane of separation.
Jointing
Series of linear mountain chains, zones of high relief.
Orogenic belts
Cycle of transformation that affects all rocks and involves all parts of the crust.
Rock cycle
Forms when existing rocks are modified by heat or pressure or both.
Metamorphic rocks
The crust and uppermost mantle.
Lithosphere
When magma rises and intrudes into the crust, rocks in the zone near the batholith or dike will be affected.
Contact metamorphism
Contact between the eroded strata and the strata of resumed deposition.
Unconformity
Foliated metamorphic rock, derived from granite.
Gneiss
Forms from the deposition, compression, and cementation of rock and mineral fragments.
Sedimentary rocks
Forms from the cooling and solidification of magma (molten rock)
Igenous rocks
Dropped zone at the point where the plates are moving apart.
Rift
Magma that reaches Earth’s surface
Lava
Magma inserts itself as a thin layer between strata of existing rocks without disturbing older layers.
Sill
Solid, composed of iron, magnesium, and silicon.
Lower mantle
Solid, high pressure, iron and nickel.
Inner core
