Chapter 14 - Geology and Nonrenewable Resources

Iron

material that the core is mostly made of

Mantle materials

rich in iron, silicon, oxygen, and magnesium

Crust

outermost and thinnest zone of the earth

the continental crust

underlies the continents

the oceanic crust

underlies the ocean basins

lithosphere

earth’s crust and the rigid, outermost part of the mantle

lithosphere position

floats and rides on top of the aesthenosphere

plate tectonics

movement of lithospheric plates on top of the aesthenosphere

divergent plate boundaries

the plates move apart - this occurs at mid-ocean ridges (new crust)

convergent plate boundaries

the plates move together (destroying crust)

* at most ___ boundaries, the oceanic plate is subducted, sliding underneath the continental crust

transform faults

 the plates move in opposite parallel directions

Earthquake

The faulting or later abrupt movement of stress in the earth’s crust that causes solid rock to deform until it suddenly factures and shifts along the fracture

Richter Scale

a measure of earthquake magnitude

active volcano

occurs where magma reaches the earth’s surface through a central vent or crack

Earthquakes

are vibrations in the earth’s crust caused by sudden shifts along a fault

Seismic Waves

vibrations that travel through the earth that are caused by Earthquakes

P waves (primary waves)

waves that travel through liquids, solids and gases

S waves (secondary waves)

waves that travel only through solids and are slower than P waves

L waves (surface waves)

waves that are the slowest and occur when P and S waves meet the surface

Volcanism

is any activity that includes the movement of magma towards or onto the earth’s surface

Major volcanic zones

include subduction zones, mid-ocean ridges, hot spots and the ring of fire

Volcanoes erupt because

magma under pressure at high temperatures causes the magma above to be pushed towards the surface and out the vent (opening of the volcano)

Lava

magma on the surface of the Earth that begins to harden

crater

the Funnel shaped pit at the top of the volcanic vent

calders

occurs when the magma chamber below collapses, creating a basin shaped depression

mineral

an element or inorganic compound that occurs naturally and is solid

Rock

any material that makes up a large, natural, continuous part of the earth’s crust

Igneous rock

can form below or on the earth’s surface when molten rock material (magma) cools

Sedimentary rock

forms from sediment that is weathered, transported, and deposited before pressure creates it

Metamorphosis rock

is produced when a preexisting rock is subjected to high temperatures, high pressures, chemically active fluids, or a combination of these

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mineral resource

a concentration of naturally occurring solid, liquid, or gaseous material in or on the earth’s crust that can be extracted and processed into useful materials at an affordable cost.

Deep deposits

are removed by subsurface mining where tunnels and chambers are excavated to reach deposits

Shallow deposits

are removed by surface mining

open-pit mining

machines dig holes and remove ores

in dredging

draglines scrape up underwater mineral deposits

in strip mining

overlying soil and rock is removed to access deposit

Contour strip mining

terraced strip mining

In mountain top removal

the top of the whole mountain is removed

economically depleted

when the costs of finding, extracting, transporting, and processing the remaining deposits exceed the returns

5 choice post economical depletion

recycle or reuse existing supplies, waste less, use less, find a substitute, or do without 

The depletion time

is the time it takes to use up 80% of the reserves at a given rate

The mining and processing of mineral resources can affect the environment in several ways:

* scarring and disruption of the land surface
* collapse or subsiding of the land
* air pollution from dust and toxics
* acid mine drainage
* water pollution from sedimentation and toxics