MidTerm Questions Geology
Layers of the Earth ?
* Crust * Upper mantle * Lower mantle * Outer Core * Inner Core Continental Crust - granite ( A piece of kitchen Counter Top) Oceanic Crust - the type of thin , mafic Crust that underlies the ocean basins Mantle - green mineral olivine , the rock brought to the surface in a volcano. The most volume layer of the earth , located below the Crust and above the core
Non silicate minerals
*Calcite *Dolomite *Hematite *Magnetite *Gypsum *Halite *Fluorite *Pyrite
The main layers of the Earth in correct order , from the surface moving down ?
1. Crust 2. Mantle 3. Outer core 4. Inner core
Types of volcanoes & their characteristics
1. Scoria Cone - cinder cone basaltic 100's of m's ta often found on the flanks (sides) of other volcanoes , loose pieces of scoria Smallest Volcano Ex. Swiss Cheese (Gas =Holes) 2. Shield Volcanos - basaltic gentle slopes , range from 1km across to the largest volcanoes in the world , often fed by a fissure or crater basaltic lava flow , broad and low 3. Composite Volcanos - Mostly andesite , (intermidiate) some felsic rock , steel sides - symmetrical , 1000's of m's high , large , but on average much smaller then shield volcanoes 4. Volcanic Dome - 100's of m's tall , v. Viscous felsic or intermediate magma found in crates often in other volcanoes
Hazards of A Volcano
1.Lava Flow 2.Hot gasses & Ash 3.Lahar = Floods
Risk of A Volcano
1.Loss of life & Property (human things - cities , houses and buildings) to
Some continents continue outward from shoreline from the shoreline under shallow seawater forming submerged benches called ?
Answer : continental Shelves
Curving island chain across the sea floor that are mainly volcanic in origin are called ?
Answer : island Arcs Island Arcs - A Curved Belt of volcanic islands above A subduction zone Sea mounts - A submarine mountain , Flat topped that rises above sea Floor Continental shelves - A gently Sloping , shallow area of the sea floor , underlined by thinned continental crust Abyssal plains - Flat , Region of the deep ocean floor
Which are important ways that magma can rise through the Crust ?
Answer: 1. Through fractures that can form dikes 2. Pieces of the wall rocks that break off and provide space 3. Tectonic forces can help open pathways 4. Magma is hotter and less dense than its surrounding
What is a main hazard of a shield volcano ?
Answer: Lava Flows , Mud Flows and Landslides
Earth is about ?
Answer: 4.6 billion years old
The first person to advance the idea of mobile continents or continental drift ?
Answer: Alfred Wegener
An oceanic transform plate boundary is most likely associated with ?
Answer: All Of these Mountain belt - chains of mountain That are 1000's of km long . Part of the geosphere
The distribution of natural resources is influenced by the ?
Answer: All of these
Which data were used to develop the hypothesis of continental drift ?
Answer: All of these
Which of the following acts to keep a rock solid ( instead of melting )
Answer: An increase in confining pressure
Oceanic crust is primarily ?
Answer: Basalt Basalt - A fine Grained , Dark color led mafic igneous rock
A mineral property that can be observed without using a test is ?
Answer: Cleavage
Which of the following is a location in which flood basalts erupted ?
Answer: Columbia Plateau
An igneous rock that solidifies on earths surface is called ?
Answer: Extrusive Intrusive - A igneous rock that solidifies from magma below earths surface
Which of the following is NOT a required criterion for a substance to be classified as a mineral ?
Answer: Human Made A mineral to be classified as a mineral ? 1. Naturally occurring 2. Crystalline Solid 3.inorganic
Which of the following Types of volcanic eruption have occurred on mount st . Helens since it began erupting in the 1980 ?
Answer: Pyroclastic flow - A fast moving cloud of hot volcanic gases , ash , pumice and rock fragments that generally travel down the flanks of a volcano Eruption column - A rising column of hot gases , tephra , and rock fragments that erupts high into the atmosphere
This type of volcano is relatively small and composed of volcanic cinders . What kind of volcano is it ?
Answer: Scoria come
Which of the following statements is true of the lithosphere ?
Answer: The lithosphere is composed of the cruse and the uppermost portion of the mantle
What strategy was described for interfering the environment in which a rock formed ?
Answer: comparing the characteristics of the rock to deposits from modern environments
Which layer in the earth has a composition similar to the granite ?
Answer: continental crust Core - Middle of the Earth
A divergent plate boundary is most likely associated with ?
Answer: mid - ocean Ridge Mid ocean ridge - A Under sea mountain chain where new ocean floor is produced Oceanic trench - Forms as the sub ducting plate bends down. Sediment and slices of oceanic crust collect in the trench
A mineral is light colored is a light colored , transparent, had a hardness of seven and fractures rather than cleaves . What Mineral is it ?
Answer: quartz Quartz - A rock forming silicate mineral , consisting of crystal- line silica Garnet - A silicate mineral with a distinctive shape , but nearly any color Biotite - A typical black or brown mica Muscovite - A light colored . Sheet silicate Mineral that is part of the mica family Feldspar - A very common rock forming silicate mineral that is abundant in most igneous and metamorphic rocks and sedimentary rocks
This volcano is broad and low , and is composed of basaltic lava Flows .what kind of volcano is it ?
Answer: shield Volcano Caldera - A large volcanic depression that is typically circular to elongate in shape and formed by collapse of a magma chamber
A porphyritic igneous textured indicates that ?
Answer: the rock cooled slowly and then quickly
A igneous pegmatite indicates ?
Answer: the water in the magma
Atomic Bonds
Bonds between atoms , by sharing or gaining electrons Covalent - Strongest Bond Ionic - dissolves in water Metallic - makes Metal move A lot Inter molecular force - Weak Bonds
How to identify plate Margins ?
Constructive plate Margins - tectonic Plates Are Moving Apart Destructive Plate - When Two plates Move Towards each Other , oceanic Plate forced underneath the continental Plate and is destroyed in the mantle Conservative Plate Margins - plates move in opposite directions and at different speeds . When released Major Earthquakes
Why crust thickens or thins ?
Continental crust = Thicker Oceanic crust = thinner
Wegener evidence for continental drift ?
Continents were joined together and later split and drifted apart
Evidence of sea floor spreading ?
Creates New Sea Floor as Plates Move Away from each other at the Mid - Ocean Ridge
How to identify Minerals ? Help!!!! Tests used To identify Minerals ?
Crystal Shape - Minerals that grow unobstructed have a distinct geometric shape * Non metallic >>> Cleavage & No Cleavage * Metallic No Cleavage Cleavage - Minerals break in a specific way due to internal arrangements of atoms ... Will break along the weakest bonds Color - Can be useful but not Always definitive Hardness - Fingernail (3) , Penny (5) , Glass Plate (7) Effervescence - The only Mineral that reacts strongly with delute Streak - Certain Minerals leave A certain color streak Magnetism - Magnet
Clastic vs. Crystalline
Crystalline -having the structure and form of a crystal; composed of crystals. "a crystalline rock" . Clastic - Rocks derived from pieces of other rocks Ex. Volcanoes , ocean , river or beaches
Where did the oceans come from ?
Deep inside the Earth Ex. Massive volcanoes eruptions
Density vs Weight
Density Ex . Density = Mass Of An Object. Over Volume of an Object Weight - how much downward force it exerts under the pull of gravity , weight depends on how much mass the object contains and the strength of gravity field .
What controls melt in divergent / convergent Boundaries ?
Divergent - Hot , Melts and increases in the divergent Convergent - pressure increases , Water melts overriding Crust
Types of plate boundaries / plate motion and what tectonic activity they produce ? Help !!!! Just 3
Divergent boundary - two plates move apart relative to one another ( magma fills the space between the plates ) Convergent boundary - two plates move toward one another. One plate slides under the other Transform boundary - two plates move horizontally past one another
Where does petroleum come from ?
Ex.) Reefs , plants , micrograms Reefs - accumulation of organic material Plants - buried and preserved in oxygen - poor conditions Microorganisms - buried and heated to right temp >>> mainly Where petroleum comes from ... What does petroleum form From ? Organic material
Flood Basalts
Flood basalts - large basalt lava Flows that cover vast areas Ex. Massive eruptions of basalt - hundreds of cubic meters of material !!! 1,000's Km's Multiple eruptions
How do we use water (in dams) to generate electricity ?
Generate hydroelectric power Dams to capture water from rivers or streams . Tubes within the dam guide water to flow from higher elevations to lower ones .
What drives plate tectonics ?
Heat Flow
How is fracking done ? Why do we do it ?
Hydraulic Fracturing ( fracking ) A method used to extract deposits of oil and natural gas by cracking the rock layers its trapped in . In a typical fraction operation ... high pressure water , sand And Slurry are pumped into a channel in the loaded bearing rock . And the pressure causes fracture
What type of Rocks form where ?
Igneous - Erupts from volcanoes Metamorphic - heat & pressure >>> Volcanoes Sedimentary - form from coast or pieces of other rocks Hydrothermal - water
How silicate tetrahedrons bond and how that impacts mineral shape ?
In most silicates one silicon atom is bonded with four oxygen atoms to form the negatively charged SiO4 complex this complex has a very important shape - Tetrahedrons The SiO4 complex takes the shape of a tetrahedron because the four oxygen atoms have similar atomic charges and so repel each other . The oxygen atoms move as far as possible from each other , taking positions that define the shape of tetrahedron
What determine viscosity ?
Is a measure of a materials resistance to flow It is determined by the bond between the molecules of the FLUID (magma) if the bond is strong we have high viscosity if the bond is weak we have low viscosity
What is A Volcano ?
Lava (molten rock) erupts A vent where magma & other volcanic products (ash , bombs and gas ) erupt onto earths surface - not always a cone shape
How does geology influence where we live ?
Living by the beach you have the perfect weather , and your able to live in a place that offers alot of resources to you . Compared to living in the mountains or valley .
How composition is used to classify igneous Rocks ?
Mafic - Dark minerals (dark grey , black ) Ultramafic - (Dark or Bright green !!!!) Felsic - light colored minerals (white , pink & Purple) Intermediate - In Between (grayish)
Which of the following is probably least risk for geologic hazards ?
On gentle slopes away from mountains
Textures Of igneous Rocks ?
Phaneritic - crystals (minerals) visible to the naked Eye Vesicular- visible holes (Vesicles) on the surface and/or throughout rock Glassy - looks like glass ; shiny ; no crystals (minerals) Pegmatite - very Large crystals (minerals) visible to the naked eye that are Atleast 1cm in diameter Aphanitic - crystals (minerals) not visible to the naked eye ; may have a grainy appearance Porphyritic - two distinct crystals (mineral) sizes
What does coal form from ?
Plant matter and other organic materials on the surface . Burial , compaction and heating Change the coal from one type to another improving its quality
Why is the core so Hot ?
Pressure and temperature increases as the air goes down , ( Pressure & Temp are Related ) Heavy radio active elements . When they Decay they give Heat
How to monitor Volcanoes
Seismograph - detects movement of the earth Light/Lasers - Measuring properties of the air Topography - lasers to measure height of volcano
How are Minerals Used In society ?
Silicon , Clay , Gypsum , Iron , Copper , Calcite Ex. I phones , dry Walls , Car , Ceramics and Cement , roadways , Houses , Buildings
Atoms
Smallest possible particle of a chemical element
What is A Mineral ?
Solid , inorganic naturally occurring substance with a defined chemical composition and an ordered internal structure Ex. Rocks
Source rock , reservoir rock , cap rocks ?
Source rock - A rock or sediment that contains enough organic material to produce petroleum Reservoir rock - A place that oil migrates to , and is held underground. Ex. Sponge Cap rocks - A Layer of hard , rock overlying and often sealing in a deposit of oil , gas or coal .
What Causes A rock To Melt ?
Temperature , Pressure & Water
Mount Saint Helen
This is a composite cone volcano , A earthquake caused the entire north face of the volcano to collapse , spewing red hot lava and volcanic ash over the surrounding land
How viscosity impacts eruptions ?
Viscosity the resistance to Flow dictates how fast a magma can Flow and how fast crystals and gas can move through the magma . When gas in a magma comes out of solution , movement of the resulting bubbles is resisted by the magmas viscosity. if the bubbles cannot escape the magma is potentially more explosive Felsic Magma contains a lot of silica = Explosive Eruptions Less Viscous Magma contains A lot of basalt = Non Explosive Eruptions and flows downhill smoothly
Cascade Mountains
Volcanic Mt. Saint Helen and Mt. Rainer are Apart of the cascade
