What type of magma is found at divergent boundaries?
plates move apart at a divergent plate boundary, the release of pressure produces partial melting of the underlying mantle. This molten material, known as magma, is basaltic in composition and is buoyant.
What produces magma in a divergent plate setting?
At convergent boundaries magma is formed where water from a subducting plate acts as a flux to lower the melting temperature of the adjacent mantle rock. At divergent boundaries magma forms because of decompression melting. Decompression melting also takes place within a mantle plume.
What does diverging tectonic plates produce?
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. The Mid-Atlantic Ridge is an example of divergent plate boundaries.
What happens to magma at divergent plate boundaries?
Divergent Plate Boundaries At a divergent boundary, tectonic plates move apart from one another. They never really separate because magma continuously moves up from the mantle into this boundary, building new plate material on both sides of the plate boundary.
What is formed at divergent boundary?
A divergent plate boundary often forms a mountain chain known as a ridge. This feature forms as magma escapes into the space between the spreading tectonic plates.
What type of melting occurs at divergent boundaries?
Decompression melting Decompression melting commonly occurs at divergent plate boundaries, where two tectonic plates are moving away from each other. Mid-ocean ridges are the classic example, but adiabatic melting also occurs during continental lithospheric extension and in some mantle plumes.
What type of magma is found at convergent boundaries?
generation. Granitic, or rhyolitic, magmas and andesitic magmas are generated at convergent plate boundaries where the oceanic lithosphere (the outer layer of Earth composed of the crust and upper mantle) is subducted so that its edge is positioned below the edge of the continental plate or another oceanic plate.
Which of the following will be formed during the movement of divergent plate boundaries?
Valleys and oceanic ridges are formed at divergent plate boundaries.
What would be the result of features found at divergent boundaries?
Effects that are found at a divergent boundary between oceanic plates include: a submarine mountain range such as the Mid-Atlantic Ridge; volcanic activity in the form of fissure eruptions; shallow earthquake activity; creation of new seafloor and a widening ocean basin.
How is magma generated at divergent boundaries quizlet?
Divergent boundaries-(Decreased Pressure)volcanic activity occur where the plates pull apart. Mantle rock rises and fills gaps between plates. As rock rises decompression melting occurs (less pressure/lower temp to melt). Magma forms and erupts along axis of the spreading center.
What types of landforms are formed at divergent plate boundaries?
Answer and Explanation: Two landforms that are created from divergent boundaries are rift valleys and mid-oceanic ridges.
What landforms are created at divergent boundaries?
At DIVERGENT boundaries the plates move apart allowing molten magma to rise and form new crust in the form of ridges, valleys and volcanoes. Landforms created by divergent plates include the Mid Atlantic Ridge and the Great African Rift Valley.
What geologic feature is formed between the diverging oceanic plates?
A divergent plate boundary often forms a mountain chain known as a ridge. This feature forms as magma escapes into the space between the spreading tectonic plates.
Which type of plate boundary generates the greatest quantity of magma?
The greatest volume of magma is produced along the oceanic ridge system in association with seafloor spreading.
How is magma generated along convergent plate boundaries quizlet?
How is magma generated along convergent plate boundaries? –Friction from the subducting slab raises the temperature of the rock under which it subducts, melting this rock into magma.
What are the formations occur during divergence?
Divergent (Spreading):This is where two plates move away from each other. Molten rock from the mantle erupts along the opening, forming new crust. The earthquakes that occur along these zones, called spreading centers, are relatively small.
Which three features can be found at divergent plate boundaries?
Effects that are found at a divergent boundary between oceanic plates include: a submarine mountain range such as the Mid-Atlantic Ridge; volcanic activity in the form of fissure eruptions; shallow earthquake activity; creation of new seafloor and a widening ocean basin.
What are the 3 types of magma?
It also contains small amounts of dissolved gases such as water vapor, carbon dioxide, and sulfur. The high temperatures and pressure under Earth's crust keep magma in its fluid state. There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition.
What happens when plates diverge on land?
Plate Divergence on Land When plate divergence occurs on land, the continental crust rifts, or splits. This effectively creates a new ocean basin as the pieces of the continent move apart. In continental rifting, magma rises beneath the continent, causing it to become thinner, break, and ultimately split apart.
What is mafic magma?
Describes magma that contains lower amounts of silica and is generally less viscous and less gas-rich than silicic magma. Tends to erupt effusively, as lava flows. Includes andesites (57-63 percent SiO2), basaltic andesites (53-57 percent SiO2), and basalts (47-53 percent SiO2).
What type of magma is basaltic?
Basaltic lava is another term for mafic lava. Mafic lava is molten rock that is enriched in iron and magnesium and low in silica. When mafic lava cools on the earth's surface, it forms basalt, which is why mafic lava is commonly called 'basaltic lava.
What forms when a divergent boundary occurs on land?
Divergent boundaries within continents initially produce rifts, which eventually become rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges.
What produces felsic magma?
Partial melting of country rock makes the magma more felsic. Partial or complete melting of xenoliths makes the magma more felsic. Possible re-melting of olivine or pyroxene can make the lower magma more mafic.
What is felsic magma?
Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava. Felsic rocks are usually light in color and have specific gravities less than 3.
Where are andesitic magmas produced?
convergent plate boundaries Granitic, or rhyolitic, magmas and andesitic magmas are generated at convergent plate boundaries where the oceanic lithosphere (the outer layer of Earth composed of the crust and upper mantle) is subducted so that its edge is positioned below the edge of the continental plate or another oceanic plate.
How is andesitic magma formed?
Andesitic magma is formed through wet partial melting of the mantle. The mantle under the ocean has contact with water. When subduction, or continental plates pulling away from one another, occurs, the mantle will heat up and water is pushed into it.
What happens when continental plates diverge?
When two continental plates diverge, a valleylike rift develops. This rift is a dropped zone where the plates are pulling apart. As the crust widens and thins, valleys form in and around the area, as do volcanoes, which may become increasingly active.
How is mafic magma produced?
In general, melting of a mantle source (garnet peridotite) results in mafic/basaltic magmas. Melting of crustal sources yields more siliceous magmas. In general more siliceous magmas form by low degrees of partial melting. As the degree of partial melting increases, less siliceous compositions can be generated.
What is rhyolitic magma?
Rhyolitic lavas are viscous and tend to form thick blocky lava flows or steep-sided piles of lava called lava domes. Rhyolite magmas tend to erupt explosively, commonly also producing abundant ash and pumice.
Where is rhyolitic magma found?
Rhyolite has been found on islands far from land, but such oceanic occurrences are rare. The tholeiitic magmas erupted at volcanic ocean islands, such as Iceland, can sometimes differentiate all the way to rhyolite, and about 8% of the volcanic rock in Iceland is rhyolite.