Scribd
Upload
133 views4 pages

The Evolution of Ocean Basin

Ocean basins evolve over time due to plate tectonic processes. They originate from continental rifting and spreading at mid-ocean ridges, which creates new ocean crust. As the ocean basin widens over time, its structure develops with features like continental shelves, slopes, rises and abyssal plains. Eventually, subduction zones form which cause the basin to shrink and be consumed, ending its evolution and leaving behind a relict scar. The five major ocean basins are the Pacific, Atlantic, Indian, Arctic, and Southern Ocean basins.

Uploaded by

Jun Gabriel Bornales
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
133 views4 pages

The Evolution of Ocean Basin

Ocean basins evolve over time due to plate tectonic processes. They originate from continental rifting and spreading at mid-ocean ridges, which creates new ocean crust. As the ocean basin widens over time, its structure develops with features like continental shelves, slopes, rises and abyssal plains. Eventually, subduction zones form which cause the basin to shrink and be consumed, ending its evolution and leaving behind a relict scar. The five major ocean basins are the Pacific, Atlantic, Indian, Arctic, and Southern Ocean basins.

Uploaded by

Jun Gabriel Bornales
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
You are on page 1/ 4

The evolution of Ocean Basin

Ocean basin

 are a consequence of plate motion


 subducting slabs pull on their plates, leading to spreading at divergent plate boundaries
 are partially bounded by continents
 interconnected - "world ocean"

Major Ocean Basins


1. Pacific basin
2. Atlantic basin
3. Indian basin
4. Arctic basin
5. Southern basin

The Structure of Ocean Basins


The continental margins of major features of the ocean floor are:

 Continental Shelf (less than 150 meters of water depth)


 Continental Slope (depth up to 1200 meters)
 Continental Rise (at the base of the continental Slope)

Types of Margins
Passive (hundreds of kilometer wide)
Inactive surface is slow to change and does little more that collect sediment.

Active (less than 1 kilometer wide)


Active ocean basins have a lot of new structures being created and shaped.

The Structure of Ocean Basins

 Each canyon's thick fan-shaped sedimentary deposit is called abyssal fans


 The ocean floor is found at the base of the continental rise in water 4000 to 6000 meters deep.

 Scientist estimate that there are approximately 10,000 volcanoes on the ocean floor
Mid-ocean Ridge

 above the ocean floor


 at the center of the ocean basins
 23% of the earth's surface
 long linear mountain chain in all oceans and bound basins
 Fracture zones are perpendicular to ridges

Deep Ocean Basins

 greater that 4000m in water depth, typically flat or subdued topography


 regularly cut by long fracture zones

Ocean Trenches Ocean Rises


mark the transition between Seamounts: guyots, atolls,
continents and ocean basins all forms of submarine
volcanoes, submarine plateaus

How did ocean basins evolve?


Stages of Ocean Basin Evolution
(Wilson Cycle)
1. Embryonic
2. Juvenile
3. Mature
4. Declining
5. Terminal
6. Relict Scar

1. Embryonic
 Continental rifting plays a key role in the formation of an ocean.
 New basin will become part of the eventual continental shelf-slope-rise zone.

2. Juvenile
 Seafloor basalt begin forming
 Fairly shallow
 Normal marine sedimentation of muds, sands and limestones, depending on local
conditons

3. Mature
 Broad as it widens
 Fairly shallow
 Trenches develop and subduction begins.
 Abyssal plains form
 Fully-develop shelf-slope-rise zone

4. Declining
 Subduction eliminates much of sea floor and
oceanic ridge.
 Dominant motions are spreading and
shrinking

5. Terminal
 African Plate is being consumed under the European Plate.
6. Relict Scar

 Shrinking and uplifting of young mountains

You might also like