Cosmology
The study of the origin, evolution, and nature of the universe
Stratification
The layering in sedimentary rocks; Layers less than 1 cm are laminations, bedding is thicker.
Orogeny
An episode of mountain building involving deformation;usually accompanied by igneous activity, metamorphism, and crustal thickening.
Angular Unconformity
An unconformity below which strata dip at a steeper angle than those above.
Disconformity
A type of unconformity above and below which the strata are parallel.
Nonconformity
An unconformity is which stratified sedimentary rocks overlie and erosion surface cut into ingenious or metamorphic rocks.
Big Bang Theory
The evolution of the universe came from a dense, hot state followed by expansion, cooling and a less dense state.
Magnetic Field
The area in which magnetic substances are affected by lines of magnetic force emanating from the Earth. (Magnetism is caused by the spin of electrons)
Age of Universe
14.7 Billion years
Age of Earth
4.5 Billion years
Terrestrial Planets
Mercury, Venus, Earth, Mars
Red Shift
Light emitted from distant galaxies that shows that the universe is expanding. Velocity increases with increasing distance (Raisin Bread example)
Earths Atmosphere Components
Nitrogen and Oxygen
Geological Time Scale-Today
Phanerzoic-Cenozoic-Quaternary-Holocene
Geological Time Scale- Relative dating
Discovered first!
Geological Time Scale- Numerical dating
(same as absolute) Obtained the numbers because of radiometric dating-date are obtained from the natural rates of decay of various radiometric elements.
Geological Time Scale Era's
Precambrian-Paleozoic- Mesozoic- Cenozoic
Sea Floor Spreading
the origin of new oceanic crust at spreading ridges that then moves away from ridges and is eventually consumed t subduction zones
Sea-floor spreading is driven by volcanic activity where?
along mid-ocean ridges. NOT folded mountain belts.
Plate Tectonics
Lithospheric plates move with respect to one another at divergent, convergent, and transform plate boundaries.
Plate Tectonics & Sea Floor Spreadin= Continental drift
Answered the big question of how continents moved!
Convergent
Where plate destruction occurs. When two plates collide and one of them is subducted back into the earth
Divergent
Where plates are separating and new oceanic lithosphere is forming. Most commonly form along the crests of oceanic ridges.
Transform
Where the plates slide laterally past one another
Slab Pull
Causes subduction. The subducting cold slab of lithosphere is denser than the surrounding warmer asthenosphere and pulls the rest of the plate as it descends into the asthenosphere.
Hot Spots
the location on Earth's surface where a stationary column or magma has slowly risen to the surface and formed a volcano. The hot spot remains stationary and leaves a trail of extinct volcanoes. CAUSED BY: Rising mantle plume or lava
Sea Trenches
A trench marks the position at which the flexed, subducting slab begins to descend beneath another lithospheric slab.
Composition of the Ocean Floor
Basalt rocks
KNOW THIS!
Both continental and oceanic crusts can form a plate
What are the 7 mineral groups?
Carbonate, Halide,Phosphate, Oxide, Silicate, Sulfate, Sulfide.
Which mineral group is most common?
Silicates
KNOW THIS
No cleavage=fractures
What are the chemical/mineral physical characteristics of the Earth?
1-Core 2-Mantle 3-Core
What is the rigidity of ht earth based on physical characteristics?
1-Inner Core 2-Outer Core 3-Mesosphere 4-Asthenosphere 5-Lithosphere
Who came up with continental drift?
Alfred Wegner
Continental Drift
The hypothesis that all continents were once joined together in a single land mass that broke apart, and moved. Named land= Pangea
James Hutton
Founder of modern geology- uniformitarianism=the present is key to the past (lightning example)
Superposition
Basis for relitive dating of strata and their contained fossils. Oldest on bottom
Original Horizontality
______
______
/////
/////
Material was once horizontal, must have been tilted. Not igneous rock, only sedimentary
Original continuity
--_____--
---___---
--------- Once continuity but something eroded it like a river. Sediment extends laterally in all directions until it thins and pinches out against a depositional basin.
Igneous Rocks
formed when magma or lava cools and crystalizes and when pyroclastic materials become consolidated.
Magma
Molten rock material BELOW the surface
Lava
Magma the reaches the surface; ABOVE
Igneous vs. Metamorphic and Melting
Igneous=melt and crystalize
Metamorphic= any rock altered in the solid state from preexisting rocks by any combination of heat and/or pressure.
Contact Metamorphism
Metamorphism taking place adjacent to a body of magma or beneath a lava flow from heat and chemically active fluids (INTRUSION)
What does limestone metamorphose into?
MARBLE (on test)
How do you metamorphose something?
Heat and pressure-burry it deeper and deeper/layer.
Shield rocks & their age?
...Ask TA
Prof Skinners favorite plate?
Jaun de Fuca
Erosion
Transport removes sediment. From source carries it elsewhere. Running water, glaciers, wind, waves.
Weatering
Breaks down bigger to smaller A-a. Same content.
Which type of rock is most common on the surface? Interior?
Sedimentary;Igneous
Classifying sedimentary rocks
Contain evidence of their formation: Fossils, Bedding, grain size.
Clastic, Chemical/Biochemical
Regression
Top to bottom: Sand, Shale, Limestone
Transgression
Top to bottom: Limestone, Shale, Sand
Fossiliferous Limestone without ripples form where?
In the ocean-limestone was once alive!
Graded Bedding=Turbidity current(Water flow)
Just know.
How to calculate half lives?
...
How do we absolute date?
Radiometric dating
Why do we not use carbon-14 dating?
Too short of a half life-only 70,000 years
Number 64
B
Inorganic chemical sedimentary rock
Precipitates from water
Sea-floor spreading is driven by volcanic activity ________.
along mid-ocean ridges
Most of the pulling force driving plate motion is produced ________.
at subduction zones
In addition to the two primary sources, plate motion may also be facilitated by convection occurring within the ________.
Asthenosphere
Unlike the lithosphere, the asthenosphere ________.
is able to flow over long periods of time
Most of the pushing force driving plate motion is produced ________.
mid-oceanic ridges
Relative ages expressed on the geologic time scale primarily resulted from the study of _____.
fossil content and spatial relationships among sedimentary rocks
The theory of Neptunism
states that rocks precipitate from water
Numerical ages for boundaries between time units on the geologic time scale primarily resulted from the study of _____, in conjunction with relative age data.
radiometric dating of igneous rocks
The idea that the facies we see in a vertical sequence will also replace each other laterally is refered to as?
Walther's Law