Chapter 8 Flashcards
Core
the innermost zone of a planet
Mantle
above the core - containing magma
Magma
molten rock
Asthenosphere
located in the outer part of the mantle
Lithosphere
the brittle outermost layer of the planet
Crust
the chemically distinct outermost layer of the lithosphere
Hot Spots
places where molten material from the mantle reaches the lithosphere
Plate Tectonics
Earth’s lithosphere is divided into plates, most of which are in constant motion
Tectonic Cycle
the sum of the processes that build up and break down the lithosphere
Subducton
the process of one plate passing under another
Subducton
the process of one plate passing under another
Volcano
a vent in Earth’s surface that emits ash, gases, and molten lava
Volcano
a vent in Earth’s surface that emits ash, gases, and molten lava
Divergent Plate Boundaries
the location where tectonic plates move away from each other
Divergent Plate Boundaries
the location where tectonic plates move away from each other
Seafloor Spreading
as magma from the mantle reaches Earth’s surface and pushes upward and outward, new rock is formed
Seafloor Spreading
as magma from the mantle reaches Earth’s surface and pushes upward and outward, new rock is formed
Convergent Plate Boundaries
form where plates move toward one another and collide
Convergent Plate Boundaries
form where plates move toward one another and collide
Transform Fault Boundary
when plates move sideways past each other
Transform Fault Boundary
when plates move sideways past each other
Fault
a fracture in rock across which there is movement
Fault
a fracture in rock across which there is movement
Fault Zones
large expanses of rock where movement has occured
Fault Zones
large expanses of rock where movement has occured
Earthquakes
occur where the rocks of the lithosphere rupture unexpectedly along a fault
Seismic Activity
earthquake activity
Seismic Activity
earthquake activity
Epicenter
the exact point on the surface of Earth directly above the location where the rock ruptures
Richter Scale
a measure of the largest ground movement that occurs during an earthquake
Rock Cycle
the constant formation and destruction of rock
Minerals
solid chemical substances with uniform structures that form under specific temperatures and pressures
Igneous Rocks
those that form directly from magma
Intrusive Igneous Rocks
form within Earth as magma rises up and cools in place underground
Extrusive Igneous Rocks
form when magma cools above Earth’s surface
Fractures
cracks that occur when rock cools
Sedimentary Rocks
forms when sediments such as muds, sands, or gravels are compressed by overlying sediments
Metamorphic Rocks
form when sedimentary rocks, igneous rocks, or other metamorphic rocks are subjected to high temperatures and pressures
Physical Weathering
the mechanical breakdown of rocks and minerals
Chemical Weathering
the breakdown of rocks and minerals by chemical reactions, the dissolving of chemical elements from rocks, or both
Acid Precipitation
when sulfur dioxide reacts with water vapor in the atmosphere to form sulfuric acid
Acid Rain
also known as acid precipitation
Erosion
the physical removal of rock fragments from landscape or ecosystem
Deposition
the accumulation or depositing of eroded material such as sediment, rock fragments, or soil
Soil
a mix
Soil
a mix of geologic and organic components
Parent Material
the rock material underlying it from which its inorganic components are derived
O Horizon
organic horizon - most pronounced in forest soils and is also found in some grasslands
A Horizon
known as topsoil - a zone of organic material and minerals that have been mixed together
A Horizon
known as topsoil - a zone of organic material and minerals that have been mixed together
Topsoil
also known as A horizon
E Horizon
a zone of leaching, or eluviation - forms under the O horizon, or less often, the A horizon
B Horizon
commonly known as subsoil - composed primarily of mineral material with very little organic matter
C Horizon
the least weathered soil horizon - always occurs beneath the B horizon
Texture
determined by the percentages of sand, silt, and clay it contains
Cation Exchange Capacity (CEC)
the ability of a particular soil to absorb and release cations
Base Saturation
a measure of the proportion of soil bases to soil acids, expressed as a percentage
Base Saturation
a measure of the proportion of soil bases to soil acids, expressed as a percentage
Soil Degradation
the loss of some or all of the ability of soils to support plant growth
Crustal Abundance
the average concentration of an element in the crust
Ores
concentrated accumulations of minerals from which economically valuable materials can be extracted
Metals
elements with properties that allow them to conduct electricity and heat energy and perform other important functions
Reserve
the known quantity of the resource that can be economically recovered
Strip Mining
the removal of “strips” of soil and rock to expose ore
Mining Spoils
unwanted waste material - also known as tailings
Tailings
mining spoils
Open-Pit Mining
the creation of a large pit or hole in the ground that is visible from Earth’s surface
Mountaintop Removal
miners remove the entire top of a mountain with explosives
Placer Mining
the process of looking for metals and precious stones in river sediments
Subsurface Mining
begins with a horizontal tunnel dug into the side of a mountain or other feature containing the resource
