What type of volcano has felsic lava?

2020-12-24 by No Comments

What type of volcano has felsic lava?

Composite volcanoes
Composite volcanoes are made of felsic to intermediate rock. The viscosity of the lava means that eruptions at these volcanoes are often explosive (figure 2). Figure 2. Mt.

Where are felsic volcanoes found?


Felsic volcanic units/localities Age (Ma) Country/Region
Duffer Formation 3468 ± 2 Australia
Marda Tank 2734 ± 3 Australia
Kallehadlu Felsic Volcanics 2677 ± 2 India
Kovero schist belt 2754 ± 6 Finland

Is Mt St Helens mafic or felsic?

Over the past 2 Ma three very large explosive eruptions at Yellowstone have yielded approximately 900 km3 of felsic magma, about 900 times the volume of the 1980 eruption of Mt. St. Helens, but only 5% of the volume of mafic magma in the CRBG.

Are shield volcanoes felsic?

Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity. Their high volatile content makes them potentially highly explosive. Shield Volcanoes. Because mafic lava is low viscosity, when it erupts from a volcano it flows downslope away from the vent, gradually cooling and crystallizing.

Could a pluton be formed from lava?

As a magma cools, the minerals separate, are drawn to their like, and begin to grow into crystals. In plutonic rocks, magma cools slowly and the crystals have time to grow large. They can grow very large indeed in a very slow cooling pluton….Plutonic and Volcanic Rocks.

Plutonic Volcanic
Granite Basalt

What is the strongest type of volcano?

The strongest types of eruptions, with a VEI of 8, are so-called “Ultra-Plinian” eruptions, such as the one at Lake Toba 74 thousand years ago, which put out 2800 times the material erupted by Mount St. Helens in 1980. Hekla in Iceland, an example of basaltic Plinian volcanism being its 1947–48 eruption.

Do shield volcanoes erupt violently?

Eruptions at shield volcanoes are only explosive if water somehow gets into the vent, otherwise they are characterized by low-explosivity fountaining that forms cinder cones and spatter cones at the vent, however, 90% of the volcano is lava rather than pyroclastic material. These are the largest volcanoes on Earth.

Which is an example of a felsic volcano?

Felsic lava forms Stratovolcanoes which are tall, steep volcanoes. This is one of the deadliest types of volcanoes for humans. Examples of this type of felsic volcano are Mount Vesuvius and Mount Saint Helens. Both these volcanos are notorious for how explosive and deadly their eruptions where.

Which is more explosive mafic lava or felsic lava?

In general, the more felsic the magma the greater the volatile content. So mafic/basaltic volcanoes are fairly quiescent, intermediate/andesitic volcanic eruptions are moderately explosive, and felsic/rhyolitic volcanoes may be extremely explosive. So, mafic lavas are hot , low in silica and volatiles, and have relatively low viscosity.

Which is the least dangerous type of volcano?

This forms shield volcanoes, which are gently sloping large volcanoes like those in Hawaii. These tend to be one of the least dangerous forms of volcanoes. The picture below shows a volcano in Hawaii, people are in the back ground showing just how safe these types of volcanoes are in comparison to felsic volcanoes.

Why are continental rocks mafic and oceanic rocks felsic?

This is why continental rocks are felsic and oceanic rocks are mafic. The below picture is of the felsic rock granite. Mafic Volcanoes: volcanoes that produce mafic lava have a very low explosivity due to the how easily the lava flows and how few volatiles (such as oxygen and silicon) are present within the lava.