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Igneous Rock
Igneous rock is formed from cooled magma or lava. The magma turns solid as it cools, and eventually becomes rock. It is sometimes crystallized.
1,149 Questions
Why don't igneous rocks look like magma rocks if igneous rock is formed from magma?
Because that is the very definition of igneous rock.
What processes can change igneous rock into sedimentary rocks?
Weathering, erosion, deposition, compaction, and cementation.
What do ígneous rocks form from?
Igneous rocks [fire rocks] are formed either underground or above ground. Underground they are formed when the melted rock [called magma] deep within the earth becomes trapped in small pockets, and as these pockets of magma cool slowly underground the magma becomes igneous rocks. Igneous rocks are also formed when volcanoes erupt causing the magma to rise above the earth's surface. When magma appears above the earth, it is called lava. Igneous rocks are formed as the lava cools above ground. Examples of igneous rocks are granite, scoria, pumice, obsidian and basalt.
Do igneous rocks have a coarse texture?
Igneous rocks have different textures for two reasons.
The first reason is that the magma from which the igneous rocks were made can be acid (having a lot of silica in it like Granite) or basaltic (having less silica and a lot more dark minerals). The acidity of a magma has a great affect on the viscosity of the lava and this affects the texture of the rocks formed.
The second (and more important) reason relates to the speed with which the magma cools. If the magma cools quickly the crystals are small and the rocks are fine textured. If the magma cools slowly the rocks end up with big, course grained crystals.
Is magma the result of rocks being heated into liquid rock?
yes. magma is melted rock that is still underground while lava is melted rock above ground
Is a igneous rock light or heavy?
inertia: the tendency of an object to resist a change in its motion
If a light rock is being thrown at a heavy rock the light rock would probably crack or get deflected from the heavy rock, but if a heavy rock is being thrown at a light rock the light rock would most likely shatter.
A: The heavy rock has more inertia
How can you determine the absolute age of an igneous rock?
Relative age can be determined using superposition and cross-cutting relationships.
Absolute age can only be determined using radiometric dating methods, such as Rb-Sr.
Is anthracite a sedimentary or a igneous rock?
Anthracite is a metamorphic rock, not a sedimentary or igneous rock. It forms from the metamorphism of bituminous coal, under high pressure and temperature conditions deep within the Earth's crust.
Obsidian is an igneous rock. Rocks are not man-made. Man-made substances that are similar to rock include concrete and cement.
They can be formed underground or above ground. Underground, they are formed when melted rock, called magma, deep under the earth's surface is trapped in small pockets. As these pockets of magma cool slowly underground, the magma develops into igneous rocks.
Igneous rocks are also formed when volcanoes erupt, causing the magma to rise above the earth's crust. When magma appears above the earth, it is called lava. Igneous rocks are formed as the lava cools above ground.
Produced under conditions involving intense heat, igneous rock is rock formed by solidification from a molten state, especially from molten magma.
an igneous rock is a lava rock that has cooled!
How much gabbro is in olivine?
Olivine does not contain Gabbro. Gabbro can contain olivine. Usually no more than a few percent.
No. A rock go from any one of the three types to any other or even back to the same type. Any rock can be re-melted to form magma, any rock can be weathered into sediment, and most rocks can undergo metamorphism. The once exception would be high-grade metamorphic rocks, which form at such high temperatures that any further heating would melt them.
Why is it impossible for someone to see the transition from an igneous rock to a sedimentary rock?
It takes a very long time (millions of years) and occurs at high pressure deep within dense sediments. Igneous rocks form from magma or lava, then are slowly eroded into tiny particles (sand, silt, clay) that when buried and compressed may form a hard sedimentary rock. The time scale can be from millions to hundreds of millions of years.
Igneous rocks are formed from the solidification of molten rock material. There are two basic types: 1) intrusive igneous rocks such as diorite, gabbro, granite and pegmatite that solidify below Earth's surface; and 2) extrusive igneous rocks such as andesite, basalt, obsidian, pumice, rhyolite and scoria that solidify on or above Earth's surface. Pictures and brief descriptions of some common igneous rock types are shown on this page.
