What type of lava is viscous?
Felsic lava They include rhyolite and dacite lavas. With such a high silica content, these lavas are extremely viscous, ranging from 108 cP (105 Pa⋅s) for hot rhyolite lava at 1,200 °C (2,190 °F) to 1011 cP (108 Pa⋅s) for cool rhyolite lava at 800 °C (1,470 °F).
Which lava type has the lowest viscosity?
Basaltic magma has the lowest viscosity because of its composition. Basaltic magma is mostly composed of iron, calcium, and magnesium, while half or…
What is high viscosity?
A fluid that is highly viscous has a high resistance (like having more friction) and flows slower than a low-viscosity fluid. To think of viscosity in everyday terms, the easier a fluid moves, the lower the viscosity.
Is basaltic lava viscous?
A basaltic lava flow has a low viscosity due to its low SiO2 content. Eruptions associated with basaltic lava usually are not explosive due to the low silica and gas content. Gases escape more easily when silica content is low. Because of the low viscosity, basaltic lava flows spread out, forming extensive layers.
What type of magma has the lowest viscosity highest viscosity?
Basaltic magma has the lowest viscosity, so more of it reaches the surface; the more viscous rhyolitic magmas are so sluggish that they tend to be trapped deep below the surface where they cool, solidify, and grow into the larger mineral crystals of plutonic rocks.
Which has the highest viscosity?
Viscosity is a measure of how much a Substance resists flowing freely. Solids have high viscosity because they cannot flow freely.
Does lava have high viscosity?
These blocks of cooler lava will begin to pile up and slow down the flow. This lava flow forms when the basaltic magma is slightly hotter and less viscous. Magma that has a higher viscosity and silica content produces rocks that are called rhyolite and andesite.
What volcanoes have high viscosity?
These rocks form Stratovolcanoes (also called composite volcanoes), due to the higher amounts of trapped gasses and the higher viscosity.
What is andesitic lava?
Andesite is a gray to black volcanic rock with between about 52 and 63 weight percent silica (SiO2). Andesites contain crystals composed primarily of plagioclase feldspar and one or more of the minerals pyroxene (clinopyroxene and orthopyroxene) and lesser amounts of hornblende.
Which igneous composition has the highest viscosity?
Types of Magma
| Summary Table | ||
| Magma Type | Solidified Volcanic Rock | Viscosity |
|---|---|---|
| Basaltic | Basalt | Low |
| Andesitic | Andesite | Intermediate |
| Rhyolitic | Rhyolite | High |
Which of the following Magma have higher viscosity?
The magma that has the highest viscosity is rhyolitic magma.
What is basaltic lava?
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.
Is andesitic lava more viscous than basaltic?
Andesitic lava is an example of a high viscosity lava whereas balastic lava has a low viscosity, so is more runny. High silica content in the andesitic lava contributes to causing this high viscosity and low silica content in the basaltic lava means it is of a lower viscosity.
Does andesitic magma have high viscosity?
Explosive eruptions are favored by high gas content and high viscosity (andesitic to rhyolitic magmas). Explosive bursting of bubbles will fragment the magma into clots of liquid that will cool as they fall through the air.
What would magma with highest viscosity contain?
Magmas that have a high silica content will therefore exhibit greater degrees of polymerization, and have higher viscosities, than those with low-silica contents.
Which is more viscous basaltic or granitic magma?
i) In general > silica content, > viscosity of magma, believed to result from tendency of complex silica anions to form long chains of molecules before crystallization begins. Thus granitic magmas are more viscous than basaltic magmas.
Does andesitic is more viscous than felsic magma?
Non explosive eruptions are favored by low gas content and low viscosity magmas (basaltic to andesitic magmas)….Viscosity of Magmas.
| Summary Table | Magma Type | Andesitic |
|---|---|---|
| Solidified Rock | Andesite | |
| Chemical Composition | 55-65 SiO2 %, intermediate in Fe, Mg, Ca, Na, K | |
| Temperature | 800 – 1000 oC | |
| Viscosity | Intermediate |
•Sep 14, 2015
Is basaltic lava more viscous than andesitic lava?
In contrast to basaltic lava flows, andesitic lava flows have a higher SiO2 content of 52–62%, which makes the lava more viscous.
Which igneous rock has the highest viscosity?
| Summary Table | ||
|---|---|---|
| Magma Type | Solidified Volcanic Rock | Viscosity |
| Mafic or Basaltic | Basalt | Low |
| Intermediate or Andesitic | Andesite | Intermediate |
| Felsic or Rhyolitic | Rhyolite | High |
Sep 3, 2015