Tectonics Flashcards
The theory that emerged from the radical proposal of continental drift.
Plate tectonics theory
the idea that continents move about the face of the planet
continental drift
states the Earth’s rigid outer shell, or Lithosphere, is broken into numerous slabs called lithospheric plates or simply plates, which are in continual motion.
Plate Tectonics Model
The lithospheric plates move relative to each other at a very slow but continuous rate that averages _________
about 5 cm/year.
Mechanism of Plate tectonics
The lithospheric plates move relative to each other at a very slow but continuous rate that averages at about 5 cm/year.
This movement is ultimately driven by the unequal distribution of heat within Earth.
Hot material found deep in the mantle moves slowly upward and serves as one part of our planet’s internal convective system.
Cooler, denser slabs of lithosphere descend back into the mantle, setting the Earth’s rigid outer shell in motion.
The titanic, grinding movements of Earth’s lithospheric plates generate earthquakes, create volcanoes, and deform large masses
of rock into mountains.
Region where all major interactions among individual plates, therefore most deformation, occur.
PLATE BOUNDARIES
Also known as constructive boundaries for creating new rocks or slabs, these occur mainly along the oceanic ridge. This boundary is where plates move apart, resulting from upwelling of material from the mantle to create new seafloor.
DIVERGENT BOUNDARIES
The mechanism where new seafloor is created when the fractures created from the pulling apart of slabs are immediately filled with molten rock that wells up from the asthenosphere below and slowly cools to become sold.
Seafloor spreading
Zones of seafloor spreading
Spreading centers
Also known as destructive boundaries for “destroying” rocks. As two plates converge, the denser slab is bent downward, sliding beneath the other. This boundary is where plates move towards each other, resulting in subduction, or consumption of oceanic lithosphere into the mantle.
CONVERGENT BOUNDARIES
A collision between an re oceanic plate and a continental plate, where the oceanic plate subducts underneath the continental plate.
Oceanic-Continental Convergence
Plate margins where oceanic crust is being consumed.
Subduction Zones
Volcanoes along subduction zones produced on continental plates when subducted materials, as well as more voluminous amounts of asthenosphere head located above the subducted slab, melt and migrate upward onto the overriding plate.
Continental Volcanic Arc
A collision between two oceanic plates, where one is thrusted beneath the other.
Oceanic-Oceanic Convergence
A chain of volcanic structures that grew from the ocean floor.
Volcanic Island Arc
A collision between two continental plates due to the continuous subduction, bringing the continental plate colliding to another, that can cause the continental crust to buckle, fracture, shorten and thicken, which may start orogenesis.
Continental-Continental Convergence
The process of mountain-building due to the collision of continental plates.
Orogenesis
Located mostly along oceanic ridges, while some slice through continents, these conservative boundaries grind past each other without either generating new lithosphere or consuming old lithosphere.
TRANSFORM FAULT BOUNDARIES
Although the total surface area of Earth does not change, individual plates may diminish or grow in area depending on the distribution of convergent and divergent boundaries.
CHANGING BOUNDARIES
