Terms Flashcards
portion of mantle below the lithosphere
asthenosphere
the varied weather produced by weather cycles
climate
all the earth system components that determine global climate along with its changes
climate system
the process of hotter material rising and cooler material sinking
convection
the dense center of the earth
core
part of the earth’s makeup directly under our feet composed of Lowe density silicates
crust
all parts of our planet and their interactions
earth system
traces of organisms preserved in the geologic record
fossil
a very old earth science that studies earth’s shape and surface
geodesy
an electromagnet in the outer core
geodynamo
formation preserved in rocks over time
geologic record
the study of all aspects of the planet
geology
specialized subsystems that produce specific types of activity such as climate change or mountain building
geosystem
a strong outer shell under the surface of the earth
lithosphere
caused by the geodynamo inside the earth’s liquid outer core and reaches far into outerspace
magnetic field
the convecting mantle and its lithospheric plates
plate tectonic system
the idea that earth’s processes today have worked the same way throughout the geologic past
uniformitarianism
the general procedure for discovering how everything works
scientific method
allow geologists to locate earthquakes and learn about earth’s inner workings
seismic wave
the smooth curvature of earth’s surface broken by mountains and valleys
topography
large scale movement of continents
continental drift
convection in the mantle that pushes and pulls continents apart, creating new oceanic crust
seafloor spreading
a supercontinent that broke into today’s continents
Pangaea
plates move apart to form new lithosphere
divergent boundaries
plates come together and one plate is recycled into the mantle
convergent boundaries
plates slide horizontally past each other
transform fault boundaries
rifting and spreading along a mid-ocean ridge creating new oceanic lithosphere
spreading center
where one plate descends beneath the other
subduction
the result of magma producing a chain of volcanoes
island arc
the intensity of the magnetic field alternated between high and low values
magnetic anomaly
hundreds of measurements around the world
magnetic time scale
the combination of the spreading rate and the spreading direction
relative plate velocity
the boundaries between bands or contours of equal seafloor age
isochrons
evidence from rock types, fossils, and magnetization that helped reconstruct a supercontinent older than Pangaea
Rodinia
a type of narrow upwelling
mantle plume
the branch of geology that studies the composition, structure, stability, associations, etc. of minerals
mineralogy
a naturally occurring solid crystalline substance with a specific chemical composition
mineral
number of protons in the nucleus of an atom
atomic number
the sum of the masses of its protons and neutrons
atomic mass
atoms of the same element with different numbers of neutrons
isotopes
sharing electrons between reacting atoms
electron sharing
a positively charged ion
cation
a negatively charged ion
anion
the simplest form of chemical bond
ionic bond
the process in which atoms of a gas or liquid come together in the proper chemical portions and arrangement to form a solid substance
crystallization
orderly three dimensional arrays of atoms in which basic arrangement is repeated in all directions
crystals
minerals with alternative structures formed from the same chemical element or compound
polymorphs
mass per unit volume expressed in grams per cubic centimeter
density
the scale based on the ability of one mineral to scratch another
Mohs scale of hardness
the weight of a mineral divided by the weight of equal volume of pure water at 4 degrees Celsius
specific gravity
the shape in which individual crystals or aggregates of crystals grow
crystal habit
the formation of parallel layers of sediment as particles are deposited
bedding
where high pressures and temperatures extend over large regions as happens where plates collide
regional metamorphism
where high temperatures are restricted to smaller areas as in the rocks are transformed
contact metamorphism
how each rock is transformed into one of the others
rock cycle
rich deposits of minerals from which valuable metals can be recovered profitably
ores
formed around bodies of molten rock
hydrothermal solutions
deposits of precipitated minerals in the fractures
veins
deposits of ore minerals that are scattered through volumes of rock larger than veins
disseminated deposits
magma flowing onto the earth’s surface
lava
an igneous rock that forced its way into the surrounding rock and solidified without reaching earth’s surface
intrusive igneous rock
formed from fragments of lava thrown into the air
pyroclasts
made of extremely small fragments that form when escaping gases fore a fine spray of magma
volcanic ash
larger particles hurled from a volcano
bombs
frothy mass of volcanic glass
pumice
igneous rock with mixed texture in which large crystals float
porphyry
poor in iron and magnesium and rich in Celtic minerals that are high in silica
Celtic rocks
not rich in silica as Celtic rocks or as poor in it as magic rocks
intermediate igneous rocks
rocks that contain large proportions of pyroxenes and olivines
mafic rocks
consist primarily of magic minerals with a small percentage of feldspar
ultramafic rocks
the measure of a liquid’s resistance to flow
viscosity
large pools of molten rock
magma chambers
a process by which rocks of varying composition can arise from a uniform parent magma
magmatic differentiation
the process by which the crystals formed in a cooling magma are segregated from the remaining liquid rock
fractional crystallization
large igneous bodies formed deep in earth’s crust
plutons
the largest plutons
batholiths
smaller plutons
stocks
how plutons cut across the layers of the country rock that they intrude
discordant intrusions
a sheetlike body formed by the injection of magma between parallel layers of bedded country rock
sill
boundaries that lie parallel to the country rock layers whether or not those layers are horizontal
concordant intrusions
major route of magma transport in the crust
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