G10 Plate Boundaries Flashcards
states that the lithosphere is a strong rigid layer the uppermost mantle and crust that were broken into several major and minor segments called tectonic plates.
Plate Tectonics Theory
Major Plates
North America South America Pacific African Eurasian Australian-Indian Antarctic plates.
three main types of plate boundaries
divergent
convergent
transform
is formed when two plates move away from each other resulting to upward movement of molten material and formation of new seafloor
divergent boundary
landform produced by a divergent boundary
ocean floor
is formed when two plates move toward each other
convergent boundary
convergent boundary is also known
destructive margin
is where the oceanic crust is destroyed and recycled.
convergent boundary
types of convergent boundaries
oceanic-oceanic
continental-continental
When two oceanic crusts converge, the _ oceanic block sinks beneath the other.
denser
oceanic-oceanic convergence produces a
volcanic island arc or island arc
When two continental plates converge, it produces spectacular mountain ranges, also known as _, such as the Himalayas.
orogens
occurs when two plates simply slide past each other
transform fault boundary
In this type of boundary, there is no formation or destruction of the new lithosphere.
transform fault boundary
a zone in the Earth’s crust where the plates move away from each other
Divergent boundaries
also known as the spreading centers.
Divergent boundaries
is where the continents split apart and form new continental margins
Divergent boundaries
Divergent plate boundaries are considered as _ _ because it’s where the new ocean floor is generated.
constructive margins
Elevated areas in the seafloor forms mountain system called the _ _.
mid-ocean ridge
These underwater mountains are linked in chains with valleys known as _.
rift
is the main mechanism operating along divergent margins.
Seafloor spreading
continuous process occurring in mid-oceanic ridges in which both sides of the ridge move apart, causing the spreading.
Seafloor spreading
As new seafloor moves away from both sides of the ridge, more melts arise from the asthenosphere. This process is repeated in a _ _- like manner.
conveyer belt
Spreading of landmasses into two segments forms
continental rifts
areas where tectonic plates move
towards each other
Convergent plate boundaries
are often associated with subduction zones, where oceanic crust descends towards the mantle due to differences in density of the subducting plate, the asthenosphere, and the overriding plate
Convergent plate boundaries
oceanic crust descends towards the mantle due to differences in _ of the subducting plate, the asthenosphere, and the overriding plate
density
oceanic lithosphere is destroyed along trenches and is recycled back into the asthenosphere
Subduction
are long, sublinear chains of volcanoes following the orientation of ocean trenches
Arcs
the denser oceanic crust subducts under the lighter continental crus
oceanic-continental convergent margins
oceanic-continental convergent margins form
volcanic arcs
the older and much denser plate subducts under the younger plate
oceanic-oceanic convergent margins
oceanic-oceanic convergent margins form
volcanic island arcs
Convergent plate boundaries may also develop through the collision of two continental plates, by
continental-continental convergent margin
forms mountain ranges with linear elevated regions.
continental-continental convergent margin
a continuous process occurring in mid-oceanic ridges in which both sides of the ridge move apart.
seafloor spreading
.
Movement in the boundaries induces decompression melting of rocks and form new oceanic lithosphere.
-
The primary process operating in oceanic convergent margins is _
subduction
are long, sublinear chains of volcanoes following the orientation of ocean trenches.
arcs
(Divergent boundaries)occurs within a continent and is caused by opposing tensional forces that stretch and thin the lithosphere, causing the outermost crustal rocks to break through normal faulting, thus forming a continental rift
Continental rifting
(Divergent boundaries)may form between two rifted continents once the lithosphere thins sufficiently for magma to erupt along an axis
New ocean basins
form different landforms and involve different processes depending on the type of plates involved in the collision
Convergent plate boundaries
the denser oceanic crust subducts under the lighter continental crust. This process forms continental volcanic arcs.
oceanic-continental convergent margins
the older and much denser plate subducts under the younger plate. This process forms volcanic island arcs.
oceanic-oceanic convergent margins
Convergent plate boundaries may also develop through the collision of two continental plates, by
continental-continental convergent margin.
forms mountain ranges with linear elevated regions.
continental-continental convergent margin
are characterized by horizontal motion along transform fault systems parallel to the boundary separating two plates form fault systems around the world
Transform plate boundaries
are part of curvilinear breaks in the seafloor known as _
fracture zones
home to landforms including continental rifts and oceanic ridges.
Divergent plate boundaries
gives rise to landforms known as continental volcanic arcs
Convergence
forms volcanic island arcs, or simply, island arcs.
oceanic-oceanic convergence,
involves a buoyant landmass (continents, arcs) moving towards the margin of another buoyant landmass due to the subduction of an intervening seafloor forming orogenic plate.
Continental-continental (C-C) convergence
are part of curvilinear breaks in the seafloor known as fracture zones.
Transform faults
