The inner of the earth is hot. Geothermal Gradient: the warm within the earth steadily boosts with depth; theheat is from radioactive decay and also remnant warmth of the Earth"s formation.

Magma is molten absent material. As magma cools the facets within the magma combine and also crystalize right into minerals that kind an igneous rock.

You are watching: Why would lava cool more quickly than magma

Magmacools either listed below the surface ar or in ~ the surface ar (magma the reaches the surface is called lava).

As magma cools igneous absent is formed. There are two species of igneous rock:

1) Extrusive: magma get the surface of the Earth before cooling and the lava cools rapidly.

2) Intrusive: magma cools under the Earth"s surface. The magma cools very slowly.

As magma cools minerals are created into an interlocking setup prlennythewonderdog.netcing one igneous rock.


As magma cools the undergoes reaction that type minerals. The rate of cooling is really important. If the magma cools slowly then the reactions proceed for a longer period of time and the resulting mineral crystals (grains) become large. If the magma cools promptly then the reaction are lot quicker and also the mineral crystals (grains) are smaller.

Igneous rocks will have a distinctive illustration (this is referred to as texture) based upon the price of cooling (fast or slow).

Textural terms because that igneous rocks:

1. Phaneritic (coarse grained): rocks space composed the mineral grains large enough to be seen through the unaided eye. Indicitive of slow cooling, usually deep in ~ the Earth.


See more: What Did Blackbeard Do To Whitebeard, How Blackbeard Acquired Two Devil Fruit

Aphanitic (fine grained): rocks are composed the mineral seed too small to be watched by the unaided eye. Indicitive of quicker cooling, normally at or near the Earth"s surface.

3. Glassy: magma cooled so quickly that decision formation might not occur. Indicative of almost instant cooling in ~ the Earth"s surface.

4. Porphorytic: big mineral cyrstals surrounding by a good grained matrix (background). This texture forms when slow-moving cooling begins to form large mineral crystals. Prior to the magma is totally cooled the magma (and its big mineral grains) moves closer to the surface and finishes cooling at a much more rapid pace.

Igneous rocks have actually a selection of chemical composition.

1. Sialic (granitic) or felsic: rocks have actually highest silica, save on computer feldspar and ferromagnesium minerals. Rocks room light in color.

2. Intermediate (andesitic): rocks have actually less silica, contain feldspar and ferromagnesium minerals. Rocks are medium gray in color.

3. Mafic (basaltic): rocks have higher amounts the ferromagnesium minerals and less silica and also feldspar. Rocks room dark in color, black color or dark gray.

4. Ultramafic: highest amount that ferromagnesium minerals and also least amount of silica. Rocks room usually a dark eco-friendly to green-black.

Classification the Igneous Rocks

Igneous rocks room classified by both texture and also composition. Friend will discover to identify typical igneous rocks in lab.

intrusive (phaneritic)granitedioritegabbro
extrusive (aphanitic)rhyoliteandesitebasalt