Unit 4: Earth Systems and Resources Flashcards
(117 cards)
Plate tectonic theory
It states that Earth’s lithosphere is divided into a small number of plates that float on and travel independently over the mantle, with much of Earth’s seismic activity occurring at the boundaries of these plates.
Pangaea
In 1915, Alfred Wegener proposed that all present-day continents originally formed one landmass he called _.
Alfred Wegener
In 1915, proposed that all present-day continents originally formed one landmass he called Pangaea.
Seafloor Spreading Theory
geologic process in which tectonic plates —large slabs of Earth’s lithosphere —split apart from each other.
lithosphere
The is the solid, outer part of the Earth and is broken into huge sections called plates, which are slowly moving.
plates
The lithosphere is the solid, outer part of the Earth and is broken into huge sections called , which are slowly moving.
Subduction zones
These are areas on Earth where two tectonic plates meet and move toward each other, with one sliding underneath the other and moving down into the mantle.
Convergent Boundaries
These occur where two plates slide toward each other.
Cascade Mountain Range
Example of Convergent Boundaries
Divergent Boundaries
These occur when two plates slide apart from each other.
Divergent Boundaries
It can create massive fault zones in the oceanic ridge system and areas of frequent oceanic earthquakes.
Mid-Atlantic Ridge and the East Pacific Rise
Example of Oceanic Divergent Boundary
East African Great Rift Valley
Example of Continental Divergent Boundary
island arc
When two oceanic plates converge, they create an _ — a curved chain of volcanic islands rising from the deep seafloor and near a continent.
undersea trench
A deep _ is located in front of such arcs where the descending plate dips downward.
Transform boundaries
These occur where plates slide past each other in opposite directions.
The san Andreas fault
Example of Transform boundaries
Soils
These are a thin layer on top of most of Earth’s land surface.
Surface Litter
Leaves and partially decomposed organic debris.
Topsoil
Organic matter, living organisms, and inorganic materials; it is very thick in grass lands.
Zone of leaching
Dissolved and suspended materials move downward.
Subsoil
Tends to be yellowish in color due to the accumulation of iron, aluminum, humic compounds, and clay leached from A and E horizons.
Weathered Parent Material
Partially broken-down inorganic materials.
Climate
Measured by precipitation and temperature, which results in partial weathering of the parent material, which forms the substrate for soil.