Quick Answer: Is Andesitic Lava Viscous?

What is andesitic lava?

Andesite is a gray to black volcanic rock with between about 52 and 63 weight percent silica (SiO2).

At the lower end of the silica range, andesite lava may also contain olivine.

Andesite magma commonly erupts from stratovolcanoes as thick lava flows, some reaching several km in length..

Can lava melt iron?

Pretty much all rocks melt by around 1200*c, though iron doesn’t tend to melt until around 1500*c. Gold would be an exception as that melts around 1000*c. It would be nice if iron (whether it be ingots, blocks, or objects) does not melt when it comes into contact with lava/magma.

What causes magma to rise?

Magma can rise when pieces of Earth’s crust called tectonic plates slowly move away from each other. … Magma also rises when these tectonic plates move toward each other. When this happens, part of Earth’s crust can be forced deep into its interior. The high heat and pressure cause the crust to melt and rise as magma.

Is Lava viscous?

Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties.

Which lava has the highest viscosity?

rhyoliticThe magma that has the highest viscosity is rhyolitic magma.

Which magma is most explosive?

Felsic magmasA large explosive volcanic eruption is 10,000 times as powerful. Felsic magmas erupt explosively because of hot, gas-rich magma churning within its chamber. The pressure becomes so great that the magma eventually breaks the seal and explodes, just like when a cork is released from a bottle of champagne.

What are 4 types of lava?

The most common way to divide lava flows into distinct types is following: Pahoehoe lava flow, Aa lava flow, Blocky lava flow, and also Pillow lava flow. Sometimes Turbulent lava flow is also added, but the latter is only of theoretical interest to scientist because we will not see that type of lava flow in the nature.

Which type of lava is the most dangerous?

Composite volcanoes are some of the most dangerous volcanoes on the planet. They tend to occur along oceanic-to-oceanic or oceanic-to-continental boundaries because of subduction zones. They tend to be made of felsic to intermediate rock and the viscosity of the lava means that eruptions tend to be explosive.

What type of volcano has andesitic magma?

Shield volcanoes are formed by basaltic magma, typically above a mantle plume, whereas the stratovolcanoes (sometimes referred to as composite volcanoes) are formed by andesitic/rhyolitic magma. You will also come to understand the relationship between volcanic phenomena and plate tectonics.

How lava is formed?

Lava forms when magma erupts from a volcano. As pressure is released gases, dissolved in the magma, bubble out so the composition of lava changes. Most lava flows are formed by the eruption of hot (around 1200oC) basalt magma, (see video clip above).

What are the 3 major types of magma?

There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition. All types of magma have a significant percentage of silicon dioxide. Basaltic magma is high in iron, magnesium, and calcium but low in potassium and sodium.

How fast does andesitic lava flow?

But when basalt lava flows are confined within a channel or lava tube on a steep slope, the main body of the flow can reach velocities >30 km/h (19 mph). Viscous andesite flows move only a few kilometers per hour (couple feet per second) and rarely extend more than 8 km (5 mi) from their vents.

Which magma is most viscous?

Thus, basaltic magmas tend to be fairly fluid (low viscosity), but their viscosity is still 10,000 to 100,0000 times more viscous than water. Rhyolitic magmas tend to have even higher viscosity, ranging between 1 million and 100 million times more viscous than water.

What is the difference between magma and lava?

Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth’s surface.

What do you call hardened lava?

The sub-family of rocks that form from volcanic lava are called igneous volcanic rocks (to differentiate them from igneous rocks that form from magma below the surface, called igneous plutonic rocks). The lavas of different volcanoes, when cooled and hardened, differ much in their appearance and composition.