Chapter 11 (Part 2) Flashcards
(26 cards)
A radioactive parent isotope decays…
… to a stable daughter isotope.
If we know the rate of decay, we can use the ratio of the two to calculate…
…the age of the rock or mineral they are contained in.
After-life
~7-8 half-lives
Less than 1%
Half-life
Amount of time it takes for ½ of
parent isotopes to decay to daughter.
Gravity pulled heavier elements
to center of Earth to form…
…different layers.
Heat emanates from the center of the Earth by…
conduction and convection.
Why is the hot inner core solid?
Increased temperature with higher pressure.
Core
Inner - -Solid iron
Outer - Molten iron; magnetic field generated
Mantle
Lower - rigid (solid, silicates rich in iron and magnesium
Upper - more silicates
Mohorovicic (Moho)
Separates crust from upper mantle
Lithosphere
Rigid rock comprising the crust (oceanic and continental) as well as the underlying rock.
Crust
Oceanic (more dense)
Continental (less dense)
Asthenosphere
Plastic or mushy upper part of the mantle.
Convective movements in this layer drive movements of the crustal plates.
Minerals
Naturally occurring solid
Definable chemical composition
Possess a crystalline structure
Inorganic
Crystalline Structure
An ordered internal structure at the atomic scale.
Not distributed randomly.
Inorganic
Minerals must be formed by geological processes such as freezing from a melt, precipitation from solution, chemical reaction.
Igneous Rocks
Originates from the cooling of liquid hot magma.
(Igneous) Intrusive
Rocks that cool and
harden below surface → coarse
grain texture.
Felsic
High silica
Rocks light in color
(Igneous) Extrusive
Rocks that cool and
harden at the surface → fine grain texture.
Mafic
Low silica
Rocks dark in color
Igneous Formations (Intrusive)
◦ Magma
◦ Pluton
◦ Batholith
◦ Sill
◦ Dike
Igneous Formations (Extrusive)
◦ Volcano
◦ Lava
◦ Ash
Dikes
Vertical cross throughs.
