Some Review Plate Tectonics Theory: The lithosphere (crust + solid uppermost man

Question

Some Review Plate Tectonics Theory: The lithosphere (crust + solid uppermost mantle) is fractured into approximately 12 lithosphere plates (tectonic plates), which are in motion relative to each other. The plates interact at their boundaries (outer edges). These interactions result in most of the major geological features on the planet, such as volcanoes, mountain ranges, earthquakes, ocean trenches, sea floor spreading zones and mid-ocean ridges. __________________________________________________________________________________ There are 3 basic types of plate boundary interactions: 1) Divergent plate boundaries (plates move apart from each other); ````` Results: Sea floor spreading zone, mid-ocean ridge, earthquakes, volcanoes and hydrothermal vents (Sea water seeps down rock fractures where it is heated by magma and returns to the sea floor as hot springs).

Explanation / Answer

According to the plate tectonics theory the lithosphere of the earth is divided into 7 major and a dozen minor plates. These plates constantly move relative to each other. The lithosphere has rocky surface and is rigid and it consists of outermost crust and uppermost mantle. The lithosphere plates move on ductile asthenosphere layer. The energy for the movement of the plate is due to convection in the mantle. Plate boundary is the narrow zone marking the relative boundary between two plates.

There are three types of plate boundary or interactions between plates: divergent boundary eg Mid ocean ridge is a spreading ridge in which plates move laterally away from each other. New crust is formed by this process. At convergent boundary eg. western coast of South America, the two plates are moving towards each other. Here one plate subduct beneath another plate. Subduction zone is marked by a trench This results in formation of island arc volcanoes if two oceanic lithosphere collides, if the interaction between ocean and continental plates then continental margin volcanic belt is formed on the active continental belt. If two continental plates collides with each other then mountain belt is formed. Transform boundary is that where neither plates move towards each other or away from each other but slip laterally past each other. eg San Andreas fault in California. This plate boundary zones are the zones where most of the earthquakes are concentrated.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.