We determined that there are only three fundamentally different ways that plates can move with respect to one another. Finally, we related all of the various geologic features that we have studied to plate boundaries and fit our observations into the framework of Plate Tectonics. You also explored some of the physical properties of the lithospheric plates and underlying mantle: isostacy, viscosity and convection.
This week we use GIS data on earthquakes and volcanoes, allowing you to map the boundaries of the Earth's tectonic plates for yourselves. Review Plate Boundaries and Associated Structures Science in the news, courtesy of USA Today.List of Geoscience Internship Opportunities.The Paleomap Project: Follow the animations link for Earth reconstructions through time.
#Continental continental convergent boundary series
For instance, the india-Asia collision has formed the huge uplifted Tibetan Plateau, a series of mountain ranges to the north including the Tien shan and Karakoram, and deformation of the continents extends far into Asia, as far as Lake Baikal.Geological Sciences 101 Introduction to Geological Sciences
in continent-continent collisions, deformation may be very diffuse and extend beyond the normal limit of plate boundary deformation that characterizes other types of plate interactions. In some cases, subduction brings two continental plates together and they collide, forming huge mountain belts like the Himalayan mountain chain. Often, slices of the old ocean floor are caught in these collision zones (these are called ophiolites), and the process by which they are emplaced over the continents is called obduction (opposite of subduction). suture zones are complex and include folded and faulted sequences of rocks that form on the two colliding terranes and in any intervening ocean basin. Mountain belts or orogens typically mark the places where lithospheric plates have collided, and the zone that they collided along is referred to as a suture. Since the plates are in constant motion, island arcs, continents, and other terranes often collide with each other. A simple model for the origin of the continental crust is that it represents a bunch of island arcs which formed at different times and which collided during plate collisions. Island arcs are extremely important for understanding the origin of the continental crust because the magmas and sediments produced here have the same composition as the average continental crust. These volcanoes form a volcanic arc, either on a continent or over an oceanic plate, depending on which type of crust the overlying plate is composed of. since subduction zones are long narrow zones where large plates are being subducted into the mantle, the melting produces a long line of volcanoes above the down-going plate.
These melts then move upward to intrude the overlying plate, where the magma may become contaminated by melting through and incorporating minerals and elements from the overlying crust. As the oceanic slabs sink downward, they experience higher temperatures that cause the release of water and other volatiles from the subducting slab, generating melts in the mantle wedge overlying the subducting slab. Oceanic lithosphere is being destroyed by sinking back into the mantle at the deep ocean trenches in a process called subduction.
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