Where the plates meet, their relative motion determines the type of boundary:
convergent, ... In this way, the total surface of the globe remains the same. ....
Oceanic crust is formed at sea-floor ...
Oct 14, 2008 ... The theory of plate tectonics is a relatively new scientific concept. ... There are
two basic types of LITHOSPHERE: continental and oceanic. ... (magma) is less
dense than the surrounding rock, so it rises toward the surface. ... Answer: the
new crust formed along the ocean ridge crests is carried away by plate ...
Sep 15, 2014 ... Divergent boundaries -- where new crust is generated as the plates pull away
from each other. ... Illustration of the Main Types of Plate Boundaries [55 k] ... as
they transport newly formed oceanic crust away from the ridge crest. ... Magma
rises and squeezes through the widening cracks, sometimes to erupt ...
At plate boundaries where sea-floor spreading occurs, magma wells up to fill the
... Spreading centers (or oceanic ridges) are where new oceanic crust is
generated. The crust that underlies all of Earths ocean basins is formed at these
types of ... As this asthenosphere rises to the surface, the pressure on it goes way
As new sea floor is created at ridge systems plates on either side of the ridge are
... The magma that forms rises through the crust into vertical fractures to form
dikes and ... There are three types of convergent plate boundaries; oceanic-
oceanic, ... When the magma erupts at the surface a volcanic island arc is formed
on the .....
But most magma remains molten or partly molten beneath Earth's surface. ...
Decompression melting often occurs at divergent boundaries, where tectonic
plates ... The rock then cools into new crust. ... The least-dense magma rises to
the top. ... The layers of magma may be documented by the type of eruption
material the ...
Divergent boundaries -- where new crust is generated as the plates pull away
from each other. ... The three principal types of plate margins and various
associated features ..... formed because the plate moved over a stationary site of
magma upwelling, ... In Iceland, where the Mid-Atlantic Ridge rises above the sea
The ocean filled areas between the new sub-continents and the landmasses ...
takes place at four types of boundaries: divergent boundaries, where new crust is
formed; ... Magma, which is generated from the melting subduct plate, rises and
squeezes into cracks. Eventually, it reaches the surface as a volcanic eruption.
As magma reaches the lithosphere, fresh ocean crust is formed. This construction
of new ocean floor helps form linear ocean ridges that can be found .... There a
three main types of plate boundary, namely, convergent, divergent and transform
or conservative. ... Magma then rises to the surface of the rift creating volcanoes.
www.tecumseh.k12.oh.us/Downloads/Plate Tectonics 3.pdf
the way plates move, geologists identified three types of boundaries. • A ... When
molten material rises from the asthenosphere, ... magma. BA. Mid-ocean ridges,
rift valleys, and new crust mark where the sea .... In time, a volcano will form at the
surface ... the Yellowstone hot spot under the North American Plate has formed.