Evolution
of
Ocean Basin
What is Ocean Basin?
An ocean basin is a depression in the form
of a bowl that has a deep seafloor with
complicated topography.
The Five Ocean Basins:
1. Pacific Ocean
2. Atlantic Ocean
3. Indian Ocean
4. Southern Ocean
5. Arctic Ocean
Parts
of
Ocean Basin
1. Continental Shelf - a portion of the
continental crust that juts out into the
ocean is known as the continental shelf.
This leads to the creation of a shelf sea,
which is a region of relatively shallow
water.
2. Continental Slope - the slope that
separates the deep ocean floor from the
outside border of the continental shelf is
known as the continental slope. It joins the
deep ocean plain to the continental shelf.
3. Continental Rise - between the abyssal
plain and the continental slope is a lowrelief zone of deposited sediments known
as the continental rise.
4. Seamount - is a submerged mountain
that rises sharply from the ocean floor.
5. Mid-Oceanic Ridge - a seafloor mountain
range created by plate tectonics is known
as a mid-ocean ridge. Seafloor spreading
occurs along a divergent plate boundary at
this feature.
6. Abyssal Plain - a level area of the ocean
floor that is typically found near the foot
of a continental uplift. Abyssal plains
make up over 50% of the Earth's surface
and are typically found between the base
of a continental rise and a mid-ocean
ridge.
7. Trench - prominent, long, narrow
topographic depressions on the ocean floor
are known as oceanic trenches.
8. Island - are formations that emerge
from the ocean basin bottoms. Simply put,
continental islands are areas of the
continental shelf that are completely
encircled by water yet are not submerged
How does Ocean Basin
form?
Plate tectonics, weathering, and erosion combine to generate all ocean
basins. Melting rock can exit the earth's mantle and generate new
oceanic crust primarily through seafloor spreading and subduction, two
types of plate tectonic activity. Tectonic plates separate from one
another during seafloor spreading. Two tectonic plates clash and force
the heavier plate to slip over the lighter plate through subduction.
Evolution of Ocean Basin
The Wilson Cycle (John Tuzo Wilson)
A concept known as the Wilson Cycle explains how ocean
basins open and close as well as how tectonic plates subduct
and diverge during the formation and breakup of
supercontinents.
6 MAJOR STAGES IN
OCEAN BASIN
1. Embryonic stage (Stage A) - First, there is a hot area
directly beneath the stable Continental Craton. The craton, or
continent, is heated by this warm hot spot and rises as a
result. In the breakup zone, the continental crust begins to
weaken and crack, eventually causing the continent to split
into two continents with a tiny ocean eventually forming in
the centre. An illustration of stage A is the East African Rift
Valley.
2. Juvenile stage (Stage B) - At this point, the
earth's plates are beginning to spread, and a tiny
ocean has formed between the recently
separated continents. The margins of both
continents will cool down and get heavier as they
drift away, sinking beneath the newly formed
sea. We refer to this barrier as a diverging
boundary. A prime example of stage B is the Red
Sea.
3. Mature stage (Stage C) - In stage C,
spreading continues despite the formation of
a sizable ocean between two continental
boundaries. Along the diverging boundary, a
mid-ocean ridge has emerged with
considerable development. Stage C includes
the Atlantic Ocean as an example.
4. Declining stage (Stage D) - At this point, the water is
starting to close up and a subduction zone has developed. The
edge of a continent, where one tectonic plate is subducted
beneath another, is one of the simplest places for a
subduction zone to emerge. As a result of this convergent
boundary, the ocean will eventually vanish, leaving behind
only a residual ocean basin. Stage D environments include
the Pacific Ocean.
5. Terminal stage (Stage E) - The continents are on the verge
of merging at this point. Small mountains are forming in the
subduction zone as a result of magma formation. Folding (the
"bending" of earth's strata), faulting (cracks in the earth crust),
and metamorphism (a change in the composition of rocks) all
take place in the subduction zone. At this point, the water is
uneven and narrow, and the boundary is converging. The
Mediterranean Sea is one instance of stage E.
6. Suturing stage (Stage F) - This is the last phase before the
mountain range gradually erodes to form a peneplain, which
is the result of the mountains eventually eroding all the way
to sea level. Stage F is when the two colliding continents will
give rise to a mountain range. The Himalaya Mountains serve
as an illustration of this stage.
That's all,
Thank you!