OCEAN BASIN - its structure and evolution.

Editor's Notes

• #4: Let us now unravel the depths of the Earth as we unfold the structure of the ocean basin. Ask the students: Do you have similar illustration as the picture on screen? What are the significant feature you have seen?
• #16: 1. Embryonic First up we have the embryonic stage. Just like its name, embryonic is the first stage of ocean basin evolution. In this stage the rift valley is formed while the continent is begins to split. However, before that the ocean basin is experience the rifting and also volcanic at the beginning. The movement that appears in this stage is the uplift of the bottom part of the ocean. This kind of movement that allows the formed of rift valley and the splitting of the continent. On the other hand, there are some example for the embryonic stage such as the Great Rift Valley, southern Red Sea, and Eastern Africa. What you need to know is that in this very first stage you can see a complex system that is marked by the linear rift valley and or the continents. rift valley forms as continent begins to split Great Rift Valley, Eastern Africa 2. Juvenile After the embryonic stage, we have the juvenile stage. In this stage, the movement that appears and happens is the subsidence of the ocean bottom and it will spread. The subsidence and the spreading will create the deviation of the continent. And because of the diverge, the seafloor basalt will be created. So basically, when the separation happens, the gap is filled with the basalt and that is how the basalt is created. Meanwhile, Juvenile stage makes the existence of oceanic crust occur below the sea level with the shape of thin and dense. And example of the juvenile stage is the Red Sea. And also in this stage you can see that the narrow seas will match the coast perfectly.sea-floor basalts begin forming as continental sections diverge  Red Sea 3. Mature Next up, after the juvenile stage of ocean basin revolution we have the mature stage. For the mature stage, the ocean basin experience the widening, trench developing, and the start of subduction. An example for the mature stage is the Atlantic Ocean. Then, to know either the stage of the ocean basin evolution is in the mature stage or not there is a characteristic that you can know. The characteristic is the existence of the continental margins in the ocean seafloor that creates the ocean basin. -broad ocean basin widens, trenches develop and subduction begins   Atlantic Ocean
• #17: 4. Declining In the declining stage, the movement that appear and happens is the continuous of the sub-duction. And because of this, the ocean seafloor and also the ocean ridge is being eliminated. There is one example of the declining stage which is the Pacific Ocean. To know either the ocean basin is in the declining stage or not there is a character that differentiate this stage from another stages. In addition, usually the geologist will see either there is a island arcs and the island trenches around the basin edge or not. If there is, then the ocean basin is in the stage of declining -subduction eliminates much of sea floor and oceanic ridge Pacific Ocean 5. Terminal And in the terminal stage the movement that appears and happens are the uplift and the converge. The uplift and the convergence that is experienced by the ocean basin creating the ocean basin become narrow. The narrow ocean basin may be caused by sediment input that make the young mountain exist along and around the flanks. And in the terminal stage the ocean basin that has been created is shallow. Meanwhile, to let you know which ocean is in the terminal stage or not you can see the existence of the young mountains in the ocean. If the ocean or the seas are narrow, irregular, and exist the young mountains there it means that the oceans and or the seas are in the terminal stage. An example of the sea that is in the terminal stage is the Mediterranean Sea. Another example of the terminal stage is the Persian Gulf. - narrow ocean basin, possibly shallowing because of sediment input -young mountain ranges along flanks - Mediterranean Sea, Persian Gulf 6.Suturing or Continental Collision And now, we have continental collision as the last stage of ocean basin evolution. Many people also known the continental collision stage as the suturing stage. In this stage the movement that appears and happens kind of the same with the mature stage which are the uplift and the convergence. Then, what make it different from the mature stage is that in the continental collision the young mountain will grow and become the mature mountains. The changes from the young mountains become mature mountains is being caused by the collide of continents. After the elimination of seafloor and the collide of continents there will be created and or the forming of the continental mountains chain. The examples of the continental collision are the Himalaya and Tibetan Plateau.last of the sea floor is eliminated and continents collide, - forming a continental mountain chain. Himalayas and Tibetan Plateau