Types of igneous rocks

Types of igneous rocks

Generally known rock as a solid composed of natural mineral pool of more than metal and in conditions of limited consists of a metal one. It is called in this case that a single rock metal Monomineralic Rock rocks differ among themselves greatly and this difference depends on several factors including:

1 - the mineral content of the rock Mineral Content.

2 - How to nurture the rock Mode of origin.

3 - How presence Mode of occurrence.

The igneous rocks is an asset that I miss him the rest of the rock types (sedimentary mutant) So sometimes called rock initial Primary rocks as it first emerged from the rocks as a result of hardened material rocky molten lying at a depth unknown exactly in the ground, known as magma or Almajma Magma because of gradual and continuous cooling has sometimes happens that this magma rises in poor areas of the earth's crust come out in the form of lava or for his father Lava as seen in volcanic lava rapid decrease in temperature consisting volcanic rocks wounds.

That was glancing at how the emergence of igneous rocks in general is that the closer look to those how are not so easily as the physical conditions and chemical, known shortcut circumstances Alvezyukimaúah Physico - chemical conditions of Zir is the deciding factor and basic how the emergence of igneous rocks. In the sense that different types of rocks due to the chemical diversity of Zir also due to the depth at which originated and created by it.

Foundations igneous rocks rating:

There is no specific classification has the consensus of scientists igneous rocks, but there are more of the grounds of classification and those foundations can be summarized as follows:

(1) Type of Chemical:

Chemical analysis proved igneous that mostly consists of silicate minerals and this has taken the proportion of silica in the beginning as the basis for the classification of igneous rocks into four groups:

A - Acidic acidic rocks and the percentage of silica to more than 66% of the most famous examples of this type granite rocks Granite and Petrochemistry Granodiorite.

B - intermediate igneous rocks Intermediate The proportion of silica from 66 52% Among the most famous examples of this type rocks Alsaanat Syenite diorite Diorite.

C alkaline igneous rocks Basic and proportion of silica from 52 40% Among the most famous examples of this type Gabbro gabbro and basalt Basalt.

D igneous rocks above the basal Ultrabasic The percentage of silica to less than 40% of the most famous examples of this type rocks Aldunate Dunite Peridotite Peridotite.

It is worth mentioning that these percentages may change increases or decreases in some authors not only this, but there are authors who Ihsron igneous rocks in the three groups are igneous rocks acidic medium and base which followed turn differences in the proportion of silica in each group.

Scientists distinguished between two types of igneous rocks by origination site to igneous rocks underground and surface igneous rocks.

A subterranean igneous rocks and sometimes known rocks Alblutunip Plutonic rocks:

It rocks that formed at great depths in the ground and going sclerosis as a result of cooling the slow and constant under high pressure with the presence of volatile substances Volatiles, allowing for the growth of crystals minerals consisting of rock fiery recharges, which is reflected thus on the fabric of the rock itself becomes a texture coarse Goarse - grained mineral content can be discerned with the naked eye, such as granite and diorite rocks and gabbro, all of igneous groundwater, which is characterized coarse Pencejeha.

This consists of the quality of the igneous rocks as a result of hardening of lava (lava) Lava tides craters at the surface in conditions unlike circumstances constituting the rocks underground just as they are cooling rapidly, to Aath opportunity for the growth of crystals metal constituents of the rock becomes fabric in this case accurate graininess Fine - grained and perhaps does not consist of crystals at all if the sudden cooling becomes fabric in this case glass Glassy.

C igneous rocks interlaced Intrusive rocks:

Despite the presence of two types of ex-igneous rocks, some may Miz somewhat III; are igneous rocks interlaced It does not consist at great depths like plutonic rocks and consists also on the surface like volcanic rocks and was composed with each other and therefore sometimes known rocks firearms subsurface Hypabyssal rocks

It is natural in this case to be the average of any fabric that is not coarse fabric or flour, but it is the fabric of the average grain Medium - grained. These include the quality of the rock, new rock (incisors) Dykes, dams Sills etc. ... Representing a place almost compromise between igneous rocks and igneous rocks groundwater surface 0 and therefore the fabric reflects, in fact, the rate of cooling, rapid Valtbrid produces about thorough granulation tissue also produces slow cooling and large-scale homogeneous granules, a coarse granulation tissue.

However, it may Issadvina sometimes rock with texture uneven graininess ie حبيباته heterogeneous in size where it appears in the rock granules large in ground minutes graininess and called on such a fabric, fabric Alborvery Porphyritic texture and because tissue largely reflects the emergence of rock, this fabric is composed in many different ways and the most important of these ways is the change in circumstances the physical and chemical that controls the growth of crystals, Valblorat phenomenon Phenocrysts arise in depths where high pressure and cooling rate slow and regular and when moving magma the magnitude of the crystals phenomenon to a higher level within the earth's crust or even go out to surface it happens imbalance in the rate of cooling as it becomes faster arise in this case micro-sized crystals and this consists tissue Alibovary.

Description of the most important igneous rocks: -

1 Granite Granite:

Granite is one of the most famous rock and widespread and consists of quartz in the range of 20 40%, feldspar where potassium feldspar is greater than 2/3 total feldspar as a whole and also mica. One of the igneous rocks acidic groundwater coarse grain may be average or sometimes grain flour.

And Alrajulaat Rhyolite is the volcanic equivalent of granite and there in the form of lava textured glass or hidden shape and there are three other names are the types of granite equivalents differ among themselves in a fabric Alaobsidian Obsedian Alapthuston Petchstone and Albeoms (pumice) Pumice.

Valaobsidian a normal glass is often black in color and features a Bmaxrh clear turbinal 0 The Alapthuston contains a lower proportion of glass and there may be a phenomenon while crystals characterized Albeoms (pumice) light weight resulting from the large number of pores.

2 Petrochemistry Granodiorite:

Rock Nary underground acidic coarse grained It is also one of the most rock prevalent and represents this rock situation moderation between granite and diorite and where less than quartz for representing in granite while increases Albulajiokles to more than two-thirds of total feldspar not exceed feldspar potassium one third of total feldspar and hornblende and represents the equivalent Volcanic Jeranodiorit rock Aldasat Dacite.

3 Abajmati Pegmatite:

Although rocks Abajmati present accompanied by all plutonic rocks almost but they always accompany granite and Petrochemistry 0 which rocks were too rough so that there are the largest and most beautiful crystals inside veins Abajmati due to the low degree of viscosity magma and concentration components, which crystallized from metals Abajmati 0 and mineral content of Radioactive comparable to the same content with granite, much Mathtoy veins Abajmati crystals Alberal Beryl and Tourmaline Tourmaline and zircon Zircon and other minerals of economic value.

4 Alsaanat Syenite:

Bullet Jovi rock average with coarse granulation tissue which often resembles granite rock in appearance and consists mainly of potassium feldspar (Erthokles) In addition to all of hornblende and Albiotit 0 and volcanic equivalent for , is Alterakit rock Trachyte.

5 diorite Diorite:

Nary underground rock average consists of two main pillars Albulajiokles metals and hornblende and volcanic equivalent of Diorit is rock Andesite.

6 gabbro Gabbro:

Nary underground rock base consists of two main pillars Albulajiokles metals, and pyroxene. And volcanic equivalent of Gabro is basalt Basalt is of the most famous volcanic rocks and used in paving roads.

7 Peridotite Peridotite:

Nary underground rock above the base consists mainly of metal olefins as well as some minerals ultramafic like Alawjat and hornblende. That was the most important vocabulary igneous rocks and notes that we have disregarded mentioned metals Additional Accessory minerals which metals is not free of rock from the rocks for two reasons first: it is one of the few and so small not exceed approximately 2% and the second reason: it does not affect the properties of the rock itself, or even rename it.

Forms of igneous rocks Forms of Igneous Rocks:

How the magma solidifies do not allow for igneous resulting from this sclerosis take regular forms, but it can put those shapes in the following groups:

(A) groundwater blocs Massive plutons: This group includes both:

1 Batulec Batholith:

It is the largest blocks of igneous rocks and most extensive and often consist of granite rocks and Petrochemistry which is at the root of the hearts and the huge mountain ranges 0

2 Stoke: Stock

A small block for Albatulec size no larger than 100 square kilometers and are usually such forms parts of Albatholat and when erosion affect the surrounding rock rise to steep called objects. Bosses

(B) objects tablet Sheet Intrusions: It consists of Mtdakhalat Intrusions wounds on body panels differ in name by developed and include:

1 Jeddah conclusive Dyke:

Sometimes known Balqata for the shortcut, which is a nested Nary Vertical or with a marked tendency when it overlaps.

2 parallel Jeddah Sill:

And sometimes known as the dam corresponding parallel or have called for the name of the dam and the shortcut is created when magma finds a path parallel to the rock layers horizontal component antibodies, and overall the new conclusive whether or parallel thickness ranges from several centimeters to several kilometers.

1 to Akulec Lacolith:

It is a Mtdakhalat wounds resembling dams Sills is that the high pressure of the class Zir on the surface causes the curvature of the layers above the fiery overlap while the lower layers remain intact in the horizontal position diameters ranging thickness Allakulec of a few hundred meters to several kilometers.

2 Opulec Loplith:

It just Allakulec opposite as it happens curvature down any lower surface concave like Billy