What is the difference between an igneous rock and a sedimentary rock?

Question

what is igneous rock? what is sedmentary rock?

Answer 1

Sedimentary rock is one of the three main rock groups (along with igneous and metamorphic rocks) and is formed in three main ways—by the deposition of the weathered remains of other rocks (known as 'clastic' sedimentary rocks); by the deposition of the results of biogenic activity; and by precipitation from solution. Sedimentary rocks include common types such as chalk, limestone, sandstone, clay and shale. Sedimentary rocks cover 75% of the Earth's surface. Four basic processes are involved in the formation of a clastic sedimentary rock: weathering (erosion), transportation, deposition and compaction.

Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from partial melts of pre-existing rocks in either the Earth's mantle or crust. The melting is caused by one or more of the following processes -- an increase in temperature, a decrease in pressure, or a change in composition. Over 700 types of igneous rocks have been described, most of them formed beneath the surface of the Earth's crust. The word "igneous" is derived from the Latin ignis, meaning "fire".

Answer 2

"So, what is the difference between a sedimentary, igneous and metamorphic rock anyway?!?" You may ask this question over and over inside your head, (especially all you rock heads out there... just kidding.) Well here we will tear open the subject and leave nothing to hide about these three kinds of rocks.



Igneous Rock

An igneous rock usually is a lot of times made up of very large particles. Igneous rock is the same kind of rock that comes from volcanoes. I know, you can't believe that such a beautiful rock could come from the same stuff that can melt almost anything, but it's true! Take a moment to browse through some of my igneous rock pictures, rocks we actually found here in Wisconsin! That means that Wisconsin use to be a large volcanic hot spot but don't worry about lava flowing toward your Wisconsin homes anytime soon. There are currently no "living" volcanoes around in Wisconsin.



Just a little note, not all of the rocks are igneous in this picture. Only the ones that look speckled and don't look completely one color are the igneous rocks.



Sedimentary Rock

Sedimentary rock is kind of easy to explain. It is a kind of rock that was made of dirt, sediments, (hence the name sedimentary) pebbles, decaying matter, or other organic material. An example of a sedimentary rock is a fossil. Below I have some examples of sedimentary rocks.



Metamorphic Rock

Metamorphic rock is a rock that use to be an igneous or sedimentary rock. Why is it different you might ask, because it is somehow changed to make a new rock. Some of the changes that can take place is when heat is added, a lot of pressure is aplied to the rock, or other changes, as long as the rock didn't turn into a liquid during the change

Answer 3

Igneous rocks are crystalline solids which form directly from the cooling of magma. This is an exothermic process (it loses heat) and involves a phase change from the liquid to the solid state. The earth is made of igneous rock - at least at the surface where our planet is exposed to the coldness of space. Igneous rocks are given names based upon two things: composition (what they are made of) and texture (how big the crystals are). (lava)

In most places on the surface, the igneous rocks which make up the majority of the crust are covered by a thin veneer of loose sediment, and the rock which is made as layers of this debris get compacted and cemented together. Sedimentary rocks are called secondary, because they are often the result of the accumulation of small pieces broken off of pre-existing rocks. (limestone)

Answer 4

1-Formation
Igneous rock is formed through the cooling and solidification of magma or lava. Igneous rock may form with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.
Sedimentary Rocks formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles (detritus) to settle and accumulate or minerals to precipitate from a solution.

2-Abundance on the earth crust
The sedimentary rock cover of the continents of the Earth's crust is extensive, but the total contribution of sedimentary rocks is estimated to be only 8% of the total volume of the crust.
Igneous and metamorphic rocks make up 90–95% of the top 16 km of the Earth's crust by volume.


3-Mineralogical contents

Felsic Igneous rock, highest content of silicon, with predominance of quartz, alkali feldspar and/or feldspathoids: the felsic minerals; these rocks (e.g., granite, rhyolite) are usually light coloured, and have low density. While mafic Igneous rock, lesser content of silicon relative to felsic rocks, with predominance of mafic minerals pyroxenes, olivines and calcic plagioclase; these rocks (example, basalt, gabbro) are usually dark coloured, and have a higher density than felsic rocks.ultramafic rock, lowest content of silicon, with more than 90% of mafic minerals
Most sedimentary rocks contain either quartz (especially siliciclastic rocks) or calcite (especially carbonate rocks). In contrast with igneous and metamorphic rocks, a sedimentary rocks usually contains very few different major minerals. However, the origin of the minerals in a sedimentary rock is often more complex than those in an igneous rock. Minerals in a sedimentary rock can have formed by precipitation during sedimentation or diagenesis. In the second case, the mineral precipitate can have grown over an older generation of cement.

Read more at http://www.geologyin.com/2014/11/top-7-differentials-between-sedimentary.html#Zu4lWPmGBLoL5XpZ.99

Answer 5

Igneous rock comes out of volcano's it is then called lava, but once it has cooled it is called igneous rock.
Sedimentary rock is made up of layers if clay, sand ,the shells of dead sea creatures it is compressed by the weight of each layer and as time passe's by it turns into sedimentary rock.

Answer 6

sedimentary rocks have multiple layers. igneous are directly from magma and have no layers. through chemical and physical changes an igneous rock can become a sedimentary, and a sedimentary back into an igneous.

Answer 7

Sedimentary Rocks are formed by deposition of sediments for a long time. Hence those have layers in it.

Igneous Rocks are formed by cooling of Lava of Volcanic erruption.

Answer 8

The difference is in the way that they form. Igneous rocks form from the cooling of magma or lava. Sedimentary rocks form from the weathering and deposition of preexisting rock. This then forms solid layers of new rock based on the sediment from which it was formed. Metamorphic rocks form from preexisting rock that undergoes extensive heat and pressure. (These are just general answers. There are other ways in which these rock types form).

Answer 9

I do believe that igneous rock is rock formed by volcanos and sedimentary is formed by layers of sediment compressed together over time.

Answer 10

sedementary rock is formed by layers of rock and earth compacting together. igneous rock, i think comes more from just a section or from a volcanoe. i'm not sure bout the igneous tho.