What is the connection of presence of volcanoes and trenches?

What is the connection of presence of volcanoes and trenches?

In a subduction zone, some of the molten material—the former seafloor—can rise through volcanoes located near the trench. The volcanoes often build volcanic arcs—island mountain ranges that lie parallel to the trench.

Why are minerals found in places near volcanoes and trenches * 1 point?

Similar to divergent boundaries, water percolates through the hot volcanic rock and magma beneath volcanoes at subduction zones. This groundwater picks up metals as it travels within the crust, eventually forming enriched deposits of mineral resources.

Are all volcanoes connected?

Although the source of magma might ultimately be from the same process (the mantle melting), almost all volcanoes are independent of one another. That is to say: all the volcanoes in an area are not all connected to a big, underground vat of magma they all share.

How can you relate the presence of these subduction zones with volcanic activities?

Subduction zones produce volcanic arcs, curving chains of steep-sided volcanoes, for example the Aleutian Islands in Alaska. Volcanoes associated with subduction zones generally have steep sides and erupt explosively. Why are the subduction zone volcanoes so steep? The lavas erupted there are rich in silica.

Are metals found in volcanoes?

Volcanoes directly or indirectly produce or host deposits of aluminum, diamonds, gold, nickel, lead, zinc, and copper. We use most of these materials everyday and, over the course of a lifetime, consume some of them (via the products we buy and use) in great amounts.

How do mineral deposits form?

Deposits of minerals form when a medium that contains and transports mineral-making ore releases and deposits the ore. When magma or lava cools, the magma and ore carried within it crystallize to form tiny minerals in the newly-created igneous rock. Minerals found in such rock might include feldspar or mica.

Which boundary can produce volcanoes?

The two types of plate boundaries that are most likely to produce volcanic activity are divergent plate boundaries and convergent plate boundaries. At a divergent boundary, tectonic plates move apart from one another.

How can you relate the presence of subduction plates and zones with volcanic activities and magnitude of earthquakes?

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.

Why do explosive volcanic eruptions occur at subduction zones?

Subduction Zone Volcanism 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.

Where do the metals go?

A lot of the metal on Earth, especially iron, is found in its core. Metal is scattered unevenly throughout the Earth’s crust, mixed with rock and combined with oxygen and other elements. Some types of rock, such as granite, only hold trace amounts of metal.

What metals are found in lava?

Lava is mostly made of two elements — Si (the symbol for silicon) and O (the symbol for oxygen). Together, they make a very strong bond and then get together with other elements, like Fe (iron), Mg (magnesium), K (potassium), Ca (calcium), and more.

Do shield volcanoes form at divergent boundaries?

Shield volcanoes form above mantle plumes, but can also form at other tectonic settings. Sea-floor volcanism can take place at divergent boundaries, mantle plumes and ocean-ocean-convergent boundaries. [SE, after USGS (http://pubs.usgs.gov/gip/dynamic/Vigil.html)]

What are the plate tectonic settings of volcanoes?

Figure 4.3 The plate-tectonic settings of common types of volcanism. Composite volcanoes form at subduction zones, either on ocean-ocean convergent boundaries (left) or ocean-continent convergent boundaries (right). Both shield volcanoes and cinder cones form in areas of continental rifting.

What processes take place in the mantle and crust?

The mantle and crustal processes that take place in areas of volcanism are illustrated in Figure 4.4. At a spreading ridge, hot mantle rock moves slowly upward by convection (cm/year), and within about 60 km of the surface, partial melting starts because of decompression.

What is an example of a subduction-related volcano?

Mt. Garibaldi (Figures 4.1 and 4.2) is an example of subduction-related volcanism. A mantle plume is an ascending column of hot rock (not magma) that originates deep in the mantle, possibly just above the core-mantle boundary.