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Universe, Milky Way, Solar System
Objects from oldest to youngest
Red shift (Doppler shift,) galaxies observed moving away from one another, "echoes" of microwave radiation
evidence of the big bang
hydrogen
composition of the universe when it was young
dust aggregating towards the central plane, collisional coagulation
how is a planetesimal formed?
impact with a mars sized planetary body
how did the moon form?
Collapse of the Solar Nebula
What caused the solar system to form?
direct observation (rovers, landers, and humans) and indirect observation (meteorites)
how do we know about the planets in our solar system?
radiation, conduction, convection
What are the three types of heat transfer?
the tilt of Earth's axis
What causes Earth's seasons?
geosphere (mantle and plate tectonics,) atmosphere (wind,) and hydrosphere (water currents)
what parts of the earth experience convection?
seafloor spreading
The process that creates new sea floor as plates move away from each other at the mid-ocean ridges, evidenced by mid-ocean trenches and ridges
slab push
Magma pushes its way up through the crust, pushing the crust apart.
slab pull
the pulling of a tectonic plate as its edge subducts deep into the mantle
heat from inside the earth
what drives plate tectonics?
Fossils, Glaciers, complimentary coastlines, magnetic field reversals, & Rocks
evidence for plate tectonics
plate boundary
the region where two tectonic plates are in contact
volcanoes, earthquakes, and deep sea vents
what defines a plate boundary
divergent plate boundary
an area beneath the ocean where tectonic plates move away from each other
convergent plate boundary
A tectonic plate boundary where two plates collide, come together, or crash into each other.
transform boundary
A plate boundary where two plates move past each other in opposite directions
type of crust involved
what does type of plate boundary depend on?
granite, light
what is the composition and weight of continental crust
basalt, heavy
what is the composition and weight of oceanic crust
continental-continental convergence
happens where 2 continental plates collide and push up creating mountain ranges
oceanic-oceanic convergence
denser plate is subducted, deep trenches generated, volcanic island arcs generated
oceanic-continental convergence
more dense oceanic plate dives under continental plate. forms a trench. causes volcanoes, and earthquakes
Mafic
describes magma or igneous rock that is rich in magnesium and iron and that is generally dark in color, composition of magma generated at mid-ocean ridge
Felsic
Describes magma or igneous rock that is rich in feldspars and silica and that is generally light in color, composition of magma generated at oceanic-continental convergent boundary
hot spot
An area where magma from deep within the mantle melts through the crust above it. plume of hotter and lighter mantle material. stationary/does not move with other plates. theory established while studying hawaii
volcano
A weak spot in the crust where magma has come to the surface
by following volcanic trails
how can hotspots be used to track plate motion
Kimberlite
rare, ultramafic rock that can contain diamonds and other minerals formed only under very high pressures.
effusive volcanism
A type of volcanism in which the magma is very fluid and emerges gradually.
explosive volcanism
A type of volcanism in which pressure in the volcano builds up for a long time, so that an eruption much lava, rock and ash is ejected high into the air.
shield volcano
a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions. low viscosity, mafic magma.
Stratovolcano/Composite Volcano
A composite volcanic cone built of interlayered lava flows and pyroclastic materials. high viscosity, felsic magma
cinder cone
A steep, cone-shaped hill or small mountain made of volcanic ash, cinders, and bombs piled up around a volcano's opening
Caldera complex
depression formed at the summit of shield volcanoes
lava flow
the area covered by lava as it pours out of a volcano's vent
Tuff Ring
broad flat crater with low rims and shallow slope formed by a phreatomagmatic eruption
Tuff
A pyroclastic igneous rock composed of volcanic ash and fragmented pumice, formed when accumulations of the debris cement together.
Phreatomagmatic eruption
An eruption in which magma contacts cold water and contracts, either slowly, forming pillow basalts, or rapidly, forming ash.
flood basalt
Vast sheets of basalt that spread from a volcanic vent over an extensive surface of land; they may form where a rift develops above a continental hot spot, and where lava is particularly hot and has low viscosity.
gravity, atmospheric density, surface and atmospheric temperatures, cryovolcanism
factors affecting planetary volcanism
less gravity makes lava thicker
how does gravity affect volcanism?
determines how high it reaches
how does gravity and atmospheric density affect pyroclastic flow and eruptions
changes how the lava cools, hot atmosphere and surface means lava cools very slowly
how does surface temperature affect volcanism?
lost 1350 ft from top, devastated 160 sq mi of forest, mudflows, ash and debris launched 11 miles into the stratosphere
why was mount saint helens dangerous
temperature (hotter magmas are less viscous), composition, and dissolved gases in the magma
what determines magma behavior?
rhyolitic/andesitic lavas
higher silica content, more viscous
basaltic lava
low silica, flows easily
how easily gases escape from lava
how is violence of an eruption determined
Quiescent eruptions
Calm oozing of magma out of the ground produces lava flows. Usually associated with basaltic lavas of low viscosit
explosive eruption
an eruption that is thick and sticky, has a high gas content, and is high in silica
aa flow
a type of lava flow that has a jagged, blocky surface
pahoehoe flow
a lava flow with a smooth-to-ropy surface
lava tube
The empty space left when a lava tunnel drains; this happens when the surface of a lava flow solidifies while the inner part of the flow continues to stream downslope.
block lava
Lava that has a surface of angular blocks associated with material having andesitic and rhyolitic compositions
pillow lava
Basaltic ava that cools underwater, taking on a distinctive pillow-like shape as it hardens
pyroclastic material (tephra)
magma, ash and pieces of rock that are ejected into the atmosphere during an explosive volcanic eruption
pyroclastic flow
The expulsion of ash, cinders, bombs, and gases during an explosive volcanic eruption
Scoria
a glassy, mafic, igneous rock containing abundant air-filled holes
Pumice
A type of igneous rock that contains air bubbles. rhyolitic
fissure eruption
an eruption in which lava is extruded from narrow fractures or cracks in the crust
basalt plateau
a plateau built up by horizontal or nearly horizontal overlapping lava flows that erupted from fissures
lava dome
A mountain or hill made from highly viscous lava, which plugs the central conduit of volcanoes
Volcanism at convergent plate boundaries
Occurs at subduction zones, where two plates converge and the oceanic lithosphere descends into the mantle.
continental volcanic arc
mountains formed in part by volcanic activity caused by the subduction of oceanic lithosphere beneath a continent
volcanic island arc
a chain of volcanic islands generally located a few hundred kilometers from a trench where there is active subduction of one oceanic plate beneath another
intraplate volcanism
igneous activity that occurs within a tectonic plate away from plate boundaries
Large Igneous Provinces
a region in which huge volumes of lava and/or ash erupted over a relatively short interval of geologic time. basaltic
surge
a small amount of ash that separates from the main body of pyroclastic flow
Lahar
An avalanche of volcanic water and mud down the slopes of a volcano
Tsunami
A giant wave usually caused by an earthquake beneath the ocean floor.
Krakatoa
Volcano in Indonesia in 1883 that had a giant explosion and created a series of tsunamis killing 36,000
Minerals
occur naturally in rocks and soil, inorganic solids composed of 1 or more elements
Rocks
A naturally formed aggregate, or mixture, of minerals; have varied chemical compositions
elements held together by chemical bonds
how are minerals formed?
covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
ionic bond
Formed when one or more electrons are transferred from one atom to another
metallic bond
a bond formed by the attraction between positively charged metal ions and the electrons around them
van der walls bond
weak attractive force between electrical neutral atoms
Ordered internal structure
The atoms in the minerals are organized in a regular, repetitive geometric patterns or crystal structure.
Solid Solution Series
A series of minerals of identical structures that contain a mixture of 2 or more elements over a range of proportions. Ex calcic, albite
Polymorphs
Minerals with the same composition but different crystalline structures. ex. graphite, diamond
Mineral Identification
color, streak, luster, hardness, specific gravity, crystal habit, fracture/cleavage
Cleavage
A mineral's ability to split easily along flat surfaces. described by quality of break, number of planes, and angles between adjacent planes
fracture
The way a mineral looks when it breaks apart in an irregular way
Silicates
minerals that contain silicon and oxygen and usually one or more other elements. largest group of minerals
Nonsilicates
Mineral groups that lack silicas in their structures and account for less than 10 percent of Earth's crust.
No, it is organic
is coal a mineral?
Plutonic
An igneous rock that solidified at a considerable depth underground. (large crystal size)
Extrusive
fine-grained igneous rock that forms when magma cools quickly at or near Earth's surface
size of crystals and rock texture
what does rate of cooling affect
Phaneritic
coarse-grained, crystals are large enough to be seen w/out a microscope, formed by slow cooling (intrusive)
Aphanitic
fine grained
glassy
crystal unable to form; Rapid rate of cooling prevents crystals from forming
Porphyritic
rock texture characterized by large, well-formed crystals surrounded by finer-grained crystals of the same mineral
Pegmatite
late stage crystallization of silicates
basalt and gabbro
examples of mafic igneous rocks
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