Chapter 8 Flashcards
mining consequences
landscapes fragmented
road construction alters habitat
water contamination
as earth created it separates into layers according to _______
mass
core
intermost part of earths interior, mostly iron and nickel, liquid outer layer and solid inner layer
mantle
layer above the core containing magma
magma
molten rock
asthenosphere
outer layer of mantle made of semi molten rock
lithosphere
outermost layer of the earth made of mantle and crust
high temp at earths center is thought to be caused by what?
radioactive decay
hotspots
where molten material from mantle reaches lithosphere
who suggested the idea of pangea
alfred wegener
plate tectonics
theory that lithosphere is divided into plates in constant motion
ore
rock with one or more netallic minerals
reserves
the amount of resource that can be extracted profitably at current prices
undiscovered reserves
potential supplies of a mineral resource
tectonic cycle
sum of processes that build up and break down the lithosphere
plate tectonics is the _____ theory i n geology
unifying
oceanic plates
less dense
rich in iron
continental plates
less dense
movement of plates is driven by what?
convection cells in earths mantle
seafloor spreading
formation of new ocean crust as magma pushes up from mantle to surface
subduction
one plate passing under another
plate movement can create _____ which can cause ______
geographic barriers, evolution
fault
fracture in a rock caused by movement of earths crust
seismic activity
frequency and intensity of earthquakes over time
mountains grow _______ per year
1.4 inches
epicenter
the exact point above where rock ruptures
______ is the original source of all rock
magma
________ rocks are directly formed from magma
igneous
_________ rock are dark, made of iron, dominant in oceanic plates
basaltic
______ rock are light, dominant in continental plates
granitic
how are intrusive rocks formed
magma rises and cools below the surface
how is extrusive rock formed
magma rises and cools above the surface
how are sedimentary rocks formed
pressure from layers of sediment on top of one another
how are metamorphic rocks formed
rocks chemically changed from high heat and pressure
physical weathering
mechanical breakdown of rocks
_____ rocks weather more quickly than _____ rocks
coarse, fine
acid rain
rain high in sulfuric and nitric acid
soil serves as what for water
the primary filter
soil is made from _____ and _____
weathered rocks and detritus
parent material
rock material from which the inorganic compounds of soil are derived
a soils _____ determines if its nutrient rich or poor
parent material
soil degradation
loss of ability to support plant growth
O horizon
surface of soil, composed of organic material
A horizon
top soil, made of organic material and minerals
E horizon
zone of leaching, forms acidic soil under O horizon
B horizon
composed of primarily minerals
C horizon
least weathered soil horizon
texture of the soil depends on the percentage of ____, ____, and ____
silt
clay
sand
cation exchange capacity
ability of soil to absorb or release cations
base saturation
proportion of soil bases to soil acids
crustal abundance
avg concentration of an element in the crust
what are the top 5 elements in the earths crust
oxygen silicon aluminum iron calcium
surface mining
mining above the earths surface
subsurface mining
mining below the earths surface
strip mining
removal of strips of soil and rock to expose ore
mining spoils
unwanted waste from mining
mountain top removal mining
mining by first exposing top of a mountain through explosives
placer mining
hand looking for minerals in river sediments
mining consequences
can change river flow
can contaminate water supply
mining law of 1872
regulated mining of minerals, metals, fuels, and etc on federal land
surface mining control and reclamation act
regulates the environmental effects of coal mining in the u.s
