Subduction of one tectonic plate at a convergent plate boundary produces magma because the subdued plate melts when it approaches the intense heat of...

What does subduction produce?

Subduction produces lines of volcanoes over the subducting plate, parallel to the trench and perpendicular to the direction of plate motion. The types of volcanoes associated with subduction are composite volcanoes, also called stratovolcanoes They occur high in elevationl as parts of major mountain ranges.

Why does subduction produce magma?

This process, called subduction, typically forms a trench, a very deep ditch, usually in the ocean floor. As the rigid lithosphere pushes down into the hot, high-pressure mantle, it heats up. ... The increased water content lowers the melting point of the mantle rock in this wedge, causing it to melt into magma.

What features form as subduction produces magma?

Volcanic arcs form parallel to subduction zones. As one plate descends under another plate, it heats up and becomes magma. ... This magma creates a chain of volcanoes or a volcanic arc near the boundary of the top plate. There are two types of arcs: island arcs and continental arcs.

How does subduction cause melting?

In a subduction zone (like the Cascades or the Andes), where an oceanic plate slides down under another plate, that downgoing slab releases its water as it heats up. That water then rises up into the mantle above it, causing it to melt at a lower temperature and, bam!

Subduction, stratovolcano's and explosive eruptions at convergent plate boundaries

30 related questions found

How does subduction produce magma quizlet?

Magma is produced in subduction zones by melting of the oceanic crust of the subducting plate. The depth at which melting takes place in subduction zones is about: More crystal fractionation and significant crustal contamination.

How does volatile substance affect the formation of magma?

The amount of a volatile component that can dissolve in silicate melt increases with pressure. As magma ascends toward the Earth's surface, pressure de- creases, thereby decreasing the solubility of volatiles and causing them to come out of solution to form bubbles.

What type of magma is associated with subduction zones?

As the plate sinks deeper, it can reach depths of 50 to 100 miles (80-160 kilometers) were it is so hot that the crust releases fluids trapped inside. The fluid melts some of the silica-rich minerals in the overlying material producing dark, silica-poor basaltic magma.

How does subduction cause the formation of land mass?

The process where one tectonic plate slides beneath another and blends into the Earth's mantle is called subduction. As two plates grind against one another, it results in the consequence of an earthquake in the subduction zone. Usually, due to an open trench between the plates, magma spills out during the process.

What is the primary source of magma supplying a volcano over a subduction zone?

What is the primary source of magma supplying a volcano over a subduction zone? Tectonic Settings Water is a key ingredient in the generation of magmas in subduction zones, and it also influences chemical differentiation that occurs when magmas cool and crystallize in the crust.

Do subduction plate boundaries result in magma?

Magma formed above a subducting plate slowly rise into the overriding crust and finally to the surface forming a volcanic arc, a chain of active volcanoes which parallels the deep ocean trench.

Does magma come from lithosphere?

The magma, comes from the other part of the lithosphere. It's released from the upper portion of the mantle. The lithosphere's responsible for the renewal of the Earth's surface. ... Some rocks are melted down entirely, and their molten remains may return to the mantle.

Does magma come from the asthenosphere?

Magma is primarily a very hot liquid, which is called a 'melt. ' It is formed from the melting of rocks in the earth's lithosphere, which is the outermost shell of the earth made of the earth's crust and upper part of the mantle, and the asthenosphere, which is the layer below the lithosphere.

What happens in a subduction zone?

Subduction zones are plate tectonic boundaries where two plates converge, and one plate is thrust beneath the other. This process results in geohazards, such as earthquakes and volcanoes. ... Earthquakes are caused by movement over an area of the plate interface called the seismogenic zone.

Which boundaries generally produce new liquid magma?

A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust.

What happens next when there is subduction?

Subduction zones always have mountain ranges caused by plate subduction. The next is volcanic activity as a plate is subducted the pressure and heat turns it into magma. These pockets of magma find paths to the surface and create volcanoes. A good example is the subduction zone near Chile.

Why are subduction zones important?

Subduction zones are important for several reasons: ... Subduction zones drag down subducted oceanic sediments, oceanic crust, and mantle lithosphere that interact with the hot asthenospheric mantle from the over-riding plate to produce calc-alkaline series melts, ore deposits, and continental crust.

How the convection current affects the movement of tectonic plates?

Convection currents describe the rising, spread, and sinking of gas, liquid, or molten material caused by the application of heat. ... Tremendous heat and pressure within the earth cause the hot magma to flow in convection currents. These currents cause the movement of the tectonic plates that make up the earth's crust.

When the leading edge of subducting plate reaches the mantle it melts turning into?

The subducting plate causes melting in the mantle. The magma rises and erupts, creating volcanoes. These coastal volcanic mountains are found in a line above the subducting plate (figure 7). The volcanoes are known as a continental arc.

Why do subduction zones generate explosive volcanic eruptions?

The magmas in subduction zone volcanoes are often explosive, because they arrive at the surface as very sticky (viscous) and gas rich.

How is magma formed in continental rift zones?

These landscapes are a result of continental rifting, or places where the continental crust is extending and thinning. As the crust thins, the hot, buoyant upper mantle (the asthenosphere) rises. Eventually the asthenosphere upwells so close to the surface that magma that erupts onto the surface.

What causes explosive volcanic eruptions above a subduction zones?

Most explosive eruptions occur in volcanoes above subduction zones, where one tectonic plate dives beneath the other. Eighty to 120 kilometers below the surface, magma forms when the rocks of the mantle melt just above the subducting plate. ... In this zone, you will see rocks from all these areas.

How viscosity affects the movement of magma?

Heating reduces viscosity (warm syrup flows more easily than cold.) High viscosity lavas flow slowly and typically cover small areas. In contrast, low viscosity magmas flow more rapidly and form lava flows that cover thousands of square kilometers.

What are the factors that contribute to magma formation?

The factors that mainly affect in the formation of magma can be summarized into three: Temperature, Pressure and composition.

What is basaltic magma?

Basaltic lava, or mafic lava, is molten rock enriched in iron and magnesium and depleted in silica. Basaltic magmas are formed by exceeding the melting point of the mantle either by adding heat, changing its composition, or decreasing its pressure. ... Underwater, basaltic lavas are erupted as pillow basalts.