What causes some igneous rocks to have a vesicular texture?

What causes some igneous rocks to have a vesicular texture?

A vesicular texture is caused when dissolved gases and other volatile components of a magma erupt from the liquid portion due to a decrease in pressure. This causes the magma to foam up, and the resulting rock to be riddled with hole-like structures called vesicles.

Which igneous rock has a vesicular texture and a mafic composition?

Classification of Igneous Rocks

Why are extrusive igneous rocks vesicular?

When igneous rocks contain two distinct grain sizes, the texture is porphyritic, and the finer crystals are called the groundmass. The extrusive rocks scoria and pumice have a vesicular, bubble-like, texture due to the presence of vapor bubbles trapped in the magma.

Which igneous rocks have a vesicular texture and contain the minerals potassium feldspar and quartz?

Pumice is an igneous rock that contains highly vesicular textured surface. It is composed of potassium feldspar, which is pink or white in color, and quartz, which is either white or colorless.

What type of igneous rock consists of very coarse crystals?

intrusive
These crystals make a coarse-grained igneous rock called plutonic, or intrusive, igneous rock because the magma was intruded into cracks deep under the earth’s surface. These coarse-grained crystals make the rock look sugary as the flat crystal faces reflect the light in hundreds of little sparkles.

Which rock has a vesicular texture and contains the minerals potassium feldspar and quartz?

Which igneous rock has a vesicular texture and floats in water?

CINDERS have lots of VESICLES (holes created by escaping gases at the lava cools). PUMICE is a type of glassy cinder that has so much gas trapped in the rock that it will float on water.

Is obsidian vesicular or non vesicular?

Pumice and rhyolite have very similar composition but they differ in texture — pumice is highly vesicular while obsidian is massive.

What is the texture of an igneous rocks?

The texture of an igneous rock made up entirely of crystals big enough to be easily seen with the naked eye is phaneritic. Phaneritic texture is sometimes referred to as coarse-grained igneous texture. Granite, the most well known example of an intrusive igneous rock, has a phaneritic texture.

Which igneous rock has a very coarse texture and contains the mineral quartz?

Granite
Granite is a coarse-grained, light-colored, intrusive igneous rock that contains mainly quartz, feldspar, and mica minerals. The specimen above is about two inches (five centimeters) across. Peridotite is a coarse-grained intrusive igneous rock that is composed almost entirely of olivine.

What is the texture of a vesicular rock?

Vesicles are fossil bubbles. So, a rock that looks like Swiss cheese has a vesicular texture. Vesicles range in shape from spherical to elongated and in size from ~1mm to more than 1 cm. Basalts are most commonly vesicular.

What type of igneous rock has a glassy texture?

Pumice is another type of igneous rock with a glassy texture. Phaneritic (“FAN-a-RIT-ic”) rocks have mineral grains that are large enough to be seen with the naked eye or a hand lens, like this granite.

What is the difference between aphanitic and porphyritic igneous rocks?

Aphanitic texture — basalt: This is a volcanic (or extrusive) igneous rock. The grains are too small to recognize, indicating very rapid cooling at or very near the earth’s surface Porphyritic texture — andesite: This is an extrusive igneous rock.

How do you describe the texture of a rock?

The texture of a rock refers to the details of its visible character. This includes the size and quality and interrelations of its grains and the fabric they form. Larger scale features, such as fractures and layering, are considered rock structures in comparison. There are nine main types…