APES Unit 4 Part 1

Crustal abundance

The average concentration of an element in Earth’s crust

Ore

A concentrated accumulation of minerals from which economically valuable materials can be extracted

Metal

An element with properties that allow it to conduct electricity and head energy and to perform other important functions

Reserve

In resource management, the known quantity of a resource that can be economically recovered

Strip mining

The removal of overlying vegetation and “strips“ of soil and rock to expose underlying ore

Mine tailings

Unwanted waste material created during mining; chemical compounds and rock residues that are left behind after the desired metal or ore is removed

Open-Pit Mining

A mining technique that creates a large visible put or hole in the ground

Mountaintop removal

A mining technique in which the entire top of a mountain is removed with explosives

Placer mining

The process of looking for minerals, metals, and precious stones in river sediments

Subsurface mining

Mining techniques used when the desired resource is more than 100 m below the surface of the Earth

Core

the innermost zone of Earth’s interior, composed mostly of iron and nickel; it includes a liquid outer layer and a solid inner layer

Mantle

The layer of Earth above the core, containing magma, the atmosphere, and the solid upper mantle

Magma

molten rock

Asthenosphere

the layer of Earth located in the outer part of the mantle, composed of semi-molten rock

Lithosphere

the outermost layer of Earth, including the solid upper mantle and crust

Plate tectonics

the theory that the lithosphere of Earth is divided into plates, most of which are in constant motion

Earthquake

a sudden movement of Earth’s crust caused by a release of potential energy from the movement of tectonic plates

Hot spot

in geology, a place where molten material from Earth’s mantle reaches the lithosphere

Volcano

a vent in the surface of Earth that emits ash, gases, or molten lava

Tsunami

a series of waves in the ocean caused by seismic activity or undersea volcano that causes a massive displacement of water

Divergent boundary

an area below the ocean where tectonic plates move away from each other

Seafloor spreading

caused by a divergent boundary, in which rising magma forms new oceanic crust on the sea floor at the boundaries between those plates

Ex: Great Rift Valley in Eastern Africa

Convergent boundary

an area where one plate moves toward another plate and collides

Subduction

the process in which the edge of an oceanic plate moves downward beneath the continental plate and is pushed toward the center of Earth; heaviest plate slides underneath lighter plate

Island arc

a chain of islands formed by volcanoes as a result of two tectonic plates coming together and experiencing subduction

Collision zone

an area where two continental plates are pushed together and the colliding forces push up the crust to form a mountain range

Transform boundary

an area where tectonic plates move sideways past each other

Fault

a fracture in rock caused by a movement of Earth’s crust

Igneous rock

rock formed directly from magma; classified by their chemical composition as basaltic or granitic

Basaltic rock

a dark rock that contains minerals with high concentrations of iron, magnesium and calcium; dominant rock type in crust of oceanic plates

Granitic rock

rock is a lighter-colored rock made up of the minerals feldspar, mica, and quartz and contains elements such as silicon, aluminum, potassium and calcium; dominant rock type in crust of continental plates; when it breaks down due to weathering, forms sand

Sedimentary rock

form when sediments such as muds, sands, or gravels are compressed by overlying sediments

Metamorphic rock

rock that forms when sedimentary rock, igneous rock, or other metamorphic rock is subjected to high temperature and pressure

Rock cycle

the geologic cycle governing the constant formation, alteration, and destruction of rock material that results from tectonics, weathering, and erosion, among other processes

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 these processes

Acid rain

precipitation high in sulfuric acid and nitric acid

Erosion

the physical removal of rock fragments from a landscape or ecosystem

A) wind, water, and ice move soil and other materials down a slope under the force of gravity

B) living organisms cause erosion

Parent material

the underlying rock material from which the inorganic components of a soil are derived

Topography

surface slope and arrangement of a landscape

Soil horizon

a horizontal layer in a soil defined by distinctive physical features such as color and texture

O horizon

the organic horizon at the surface of many soils, composed of organic detritus in various stages of decomposition

Humus

the most fully decomposed organic matter in the lowest section of the O horizon

A horizon

frequently the top layer of soil, a zone of organic material and minerals that have been mixed tougher (topsoil)

E horizon

a zone of leaching, or eluviation, found in some acidic soils under the O horizon or, less often, the A horizon

B horizon

commonly known as subsoil, a soil horizon is composed primary of mineral material with very little organic matter

C horizon

the least-weathered soil horizon, which always occurs beneath the B horizon and is similar to the parent material

Porosity

the size of the air spaces between particles 

Large sand particles have large air spaces between particles that the much smaller clay particles, so sandy soil has a higher porosity than clay soils

Water holding capacity

the amount of water a soil can hold against the draining force of gravity

Permeability

the ability of water to move through the soil

Cation exchange capacity (CEC)

the ability of a particular soil to absorb and release cations

Overall ____ of a soil is a function of the amount and types of clay particles present

high ____ —> potential to provide essential cations to plants and therefore are desirable for agriculture

Base saturation

the proportion of soil bases to soil acids, expressed as percentage

Watershed

all the land in an area that drains into a particular stream, river, lake, or wetland

Ecological succession

the predictable replacement of one group of species by another group of species over time

Primary succession

ecological succession occurring on surfaces with bare rock and no soil

Pioneer Species

in primary succession, species that can survive with little or no soil

Secondary succession

the succession of plant life that occurs in areas that have been disturbed but have not lost their soil

Climax community

historically described as the final stage of succession

Disruption/Disturbance

A temporary event that alters an ecosystem’s structure or function by changing population sizes, resource availability, or physical conditions (e.g., fires, floods, hurricanes, human activity)

Resistance

The ability of an ecosystem to remain unchanged when a disruption occurs; ecosystems with high resistance show little change after a disturbance

Resilience

The ability of an ecosystem to recover and return to its original structure and function after a disruption

Intermediate Disturbance Hypothesis

The idea that moderate levels of disturbance result in the highest species diversity, because they prevent competitive exclusion without eliminating too many species

Periodic disruption

A disturbance that occurs at regular, predictable intervals, allowing organisms to adapt (e.g., seasonal flooding, regular wildfires in grasslands)

Episodic disruption

A rare but intense disturbance that happens irregularly and can cause major ecosystem change (e.g., volcanic eruptions, major hurricanes)

Random Disruption

A disturbance that occurs unpredictably in timing and location, making adaptation difficult (e.g., earthquakes, oil spills)