Minerals
Plate Tectonics/Earth Layers
Rocks
Geologic Time/Earth History
Misc.
100
what is the definition of a mineral?
1) naturally occurring
2) inorganic
3) solid at room temperature
4) crystal structure
5) defined chemical composition
100
what are the physical and chemical layers of earth
Chemical: Crust, Mantle, Core
Physical: Lithosphere, Asthenosphere, Mesosphere, Outer Core, Inner Core
100
define how sedimentary, metamorphic and igneous rocks from
sedimentary - when small particles of rock and minerals, called sediments, are deposited over time, then compacted and cemented together through a process called lithification
metamorphic - when existing rocks, like sedimentary or igneous rocks, are significantly changed by exposure to high heat, pressure, or chemically active fluids deep within the Earth's crust, causing a transformation in their mineral composition and texture without fully melting the rock; this process is called metamorphism.
igneous - when molten rock, called magma when underground and lava when on the surface, cools and solidifies, either deep within the Earth's crust (intrusive) or when erupted onto the surface as lava (extrusive), essentially "crystallizing" from a melted state due to decreasing temperature.
100
define uniformitarianism
"the present is the key to the past"
100
what is an unconformity
represent gaps in the geologic record; periods of time that are not represented by any rocks.
200
what is a polymorph?
A mineral with the same chemical composition but different crystal structure due to different Pressure and Temperature at formation.
200
define plate tectonics and describe the 3 types of plate boundaries
a theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates which move slowly over the underlying mantle.
1) Divergent - moving apart
2) Convergent - moving together
3) Transform - moving side by side
200
how does foliation develop in metamorphic rocks?
Foliation forms when pressure squeezes the flat or elongate minerals within a rock so they become aligned. These rocks develop a platy or sheet-like structure that reflects the direction that pressure was applied.
200
define relative and absolute dating
Relative dating does not offer specific dates, it simply allows to determine if one fossil or stratigraphic layer is older than another. Absolute dating methods provide more specific origin dates and time ranges, such as an age range in years.
200
define a stratigraphic formation
A stratigraphic formation is a recognizable sequence of beds that can be mapped across a broad region
300
what are the properties used in mineral ID?
1) luster*
2) color*
3) hardness*
4) cleavage/fracture*
5) crystal form*
6) streak*
7) tenacity
8) specific gravity
300
what is the mechanism or driving force to move plates?
1) Ridge Push = Divergent Boundaries:
Push on the plate
2) Slab Pull = Convergent Boundaries:
Pull on the plate
3) Beneath plates:
Mantle convection
300
what two criteria are used to classify igneous rocks?
1) Texture - Is dependent on cooling rate.
Aphanitic: fine crystals (cannot see with the naked eye). Rapid cooling (volcanic).
Rock Examples: Basalt, Rhyolite
Phaneritic: coarse crystals easily seen with the naked eye. Slow cooling (plutonic).
Rock Examples: Granite, Gabbro
2) Composition - Is dependent on the source material.
Ultramafic - 38 to 45% silica (peridotite)
Mafic (Mg and Fe-rich) - 45 to 52% silica (basalt, gabbro)
Intermediate - 52 to 66% silica (diorite)
Felsic (Feldspar and silica) - 66 to 76% silica (rhyolite, granite)
***BOWENS REACTION SERIES***
300
what methods are used in relative and absolute dating
Relative:
•Principle of uniformitarianism
•Principle of superposition
•Principle of original horizontality
•Principle of original continuity
•Principle of cross-cutting relationships
•Principle of inclusions
•Principle of faunal succession
Absolute:
Many relative ages can be assigned actual numerical dates because of radiometric dating or geochronology. This technique measures certain radioactive isotopes in minerals that decay at a known, fixed rate. Radioactive isotopes act as internal clocks.
300
how did the moon form?
At 4.5 billion years ago (in just a few hours) a Mars-sized planetesimal collides with proto-Earth. The core of impactor segregates and joins Earth’s. Lighter crust of both bodies melts, forming magma ocean. Large raft of debris is ejected to space. Impact knocks Earth off-kilter by 23˚, speeds rotation. Debris aggregates to form proto-Moon.
400
what are the different types of atomic binding found in minerals and describe what they mean
1) Covalent bonding
- sharing of electrons (strongest)
2) Ionic bonding
- transfer of electrons
400
what evidence did Wenger use for plate tectonics?
1st Evidence of Continental Drift: comparing similar rocks, mountains, fossils (land bridge), and glacial formations across oceans.
2nd Evidence to Continental Drift:
Glaciers - southern Africa, India, Australia, & Arabia
Tropical plant fossils- Arctic Circle
400
how does transport and erosion effect sediments?
400
How old is Earth?
4.54 ± 0.05 billion years old.
400
how did earth form?
Homogeneous earth formed from multiple impacts of material left over from Big Bang, fusion reactions in stars and supernova explosions and the material comes together. Over time differentiation begins. This is density driven and forms the different layers of earth. Denser material travels to the center of the earth (core) and the lighter material gets left on the outside (crust).
500
what are the two different ways a mineral can form and describe the processes
1) precipitation
- Ions in solution come together to form solid minerals. The ions are saturated (e.g., so many ions they don’t know where to go, so they come together to form a solid)
2) crystallization
- Magma is molten rock with freely moving ions. When magma freezes or cools, mineral forms. Many mineral crystals form when a melt solidifies. Quick cooling results in tiny crystals; slow cooling creates large crystals.
500
what is the average tectonic plate movement per year?
1.6 cm/yr
500
what are the differences between clastic/detrital, biological, organic, and chemical sedimentary rocks? Give examples of each.
1) Clastic/Detrital - Loose rock fragments (clasts) cemented together.
Rock Examples: conglomerate, breccia, sandstone, shale, mudstone
2) Chemical - Minerals that crystallize/precipitate directly from water.
Rock Examples: gypsum, halite, carbonates
3) Biochemical - Made of sediments derived from the shells of once-living organisms.
Rock Examples: limestone, coquina, chert
4) Organic - Rich on organic carbon from once living organisms/plants.
Rock Examples: coal, peat, oil shale
500
Explain isotopic dating.
Isotopic dating (radiometric dating) specifies numerical ages in years. To obtain an isotopic date, we measure the ratio of radioactive parent isotopes to stable daughter isotopes in a mineral.
500
what are the steps to the scientific method?
Steps to Scientific Process:
•Observation, Problem, Research Q
•Hypothesis
•Experiment & Revision
•Peer Review
•Theory Development