From: Tilling, 1985, Volcanoes: USGS General Interest PublicationMolten rock below the surface of the Earth that rises in volcanic vents is known as magma, but after it erupts from a volcano it is called lava. Originating many tens of miles beneath the ground, the ascending magma commonly contains some crystals, fragments of surrounding (unmelted) rocks, and dissolved gases, but it is primarily a liquid composed principally of oxygen, silicon, aluminum, iron, magnesium, calcium, sodium, potassium, titanium, and manganese. Magmas also contain many other chemical elements in trace quantities. Upon cooling, the liquid magma may precipitate crystals of various minerals until solidification is complete to form an igneous or magmatic rock.... heat concentrated in the Earth's upper mantle raises temperatures sufficiently to melt the rock locally by fusing the materials with the lowest melting temperatures, resulting in small, isolated blobs of magma. These blobs then collect, rise through conduits and fractures, and some ultimately may re-collect in larger pockets or reservoirs ("holding tanks") a few miles beneath the Earth's surface. Mounting pressure within the reservoir may drive the magma further upward through structurally weak zones to erupt as lava at the surface. In a continental environment magmas are generally in the Earth's crust as well as at varying depths in the upper mantle. The variety of molten rocks in the crust, plus the possibility of mixing with molten materials from the underlying mantle, leads to the production of magmas with widely different chemical compositions.If magmas cool rapidly, as might be expected near or on the Earth's surface, they solidify to form igneous rocks that are finely crystalline or glassy with few crystals. Accordingly, lavas, which of course are very rapidly cooled, form volcanic rocks typically characterized by a small percentage of crystals or fragments set in a matrix of glass (quenched or super-cooled magma) or finer grained crystalline materials. If magmas never breach the surface to erupt and remain deep underground, they cool much more slowly and thus allow ample time to sustain crystal precipitation and growth, resulting in the formation of coarser grained, nearly completely crystalline, igneous rocks. Subsequent to final crystallization and solidification, such rocks can be exhumed by erosion many thousands or millions of years later and be exposed as large bodies of so-called granitic rocks, as, for example, those spectacularly displayed in Yosemite National Park and other part of the majestic Sierra Nevada mountains of California.Lava is red hot when it pours or blasts out of a vent but soon changes to dark red, gray, black, or some other color as it cools and solidifies. Very hot, gas-rich lava containing abundant iron and magnesium is fluid and flows like hot tar, whereas cooler, gas-poor lava high in silicon, sodium, and potassium flows sluggishly, like thick honey in some cases or in others like pasty, blocky masses.All magmas contain dissolved gases, and as they rise to the surface to erupt, the confining pressures are reduced and the dissolved gases are liberated either quietly or explosively. If the lava is a thin fluid (not viscous), the gases may escape easily. But if the lava is thick and pasty (highly viscous), the gases will not move freely but will build up tremendous pressure, and ultimately escape with explosive violence. Gases in lava may be compared with the gas in a bottle of a carbonated soft drink. If you put your thumb over the top of the bottle and shake it vigorously, the gas separates from the drink and forms bubbles. When you remove your thumb abruptly, there is a miniatures explosion of gas and liquid. The gases in lava behave in somewhat the same way. Their sudden expansion causes the terrible explosions that throw out great masses of solid rock as well as lava, dust, and ashes.The violent separation of gas from lava may produce rock froth called pumice. Some of this froth is so light -- because of the many gas bubbles -- that it floats on water. In many eruptions, the froth is shattered explosively into small fragments that are hurled high into the air in the form of volcanic cinders (red or black), volcanic ash (commonly tan or gray), and volcanic dust. ...Most composite volcanoes have a crater at the summit which contains a central vent or a clustered group of vents. Lavas either flow through breaks in the crater wall or issue from fissures on the flanks of the cone. Lava, solidified within the fissures, forms dikes that act as ribs which greatly strengthen the cone. ...In some shield-volcano eruptions, basaltic lava pours out quietly from long fissures instead of central vents and floods the surrounding countryside with lava flow upon lava flow, forming broad plateaus. Lava plateaus of this type can be seen in Iceland, southeastern Washington, eastern Oregon, and southern Idaho. ...Volcanic or lava domes are formed by relatively small, bulbous masses of lava too viscous to flow any great distance; consequently, on extrusion, the lava piles over and around its vent. ...Congealed magma, along with fragmental volcanic and wallrock materials, can be preserved in the feeding conduits of a volcano upon cessation of activity. These preserved rocks form crudely cylindrical masses, from which project radiating dikes; they may be visualized as the fossil remains of the innards of a volcano (the so-called "volcanic Plumbing system") and are referred to as volcanic plugs or necks. The igneous material in a plug may have a range of composition similar to that of associated lavas or ash, but may also include fragments and blocks of denser, coarser grained rocks -- higher in iron and magnesium, lower in silicon -- thought to be samples of the Earth's deep crust or upper mantle plucked and transported by ascending magma. ...Lava, erupting onto a shallow sea floor or flowing into the sea from land, may cool so rapidly that it shatters into sand and rubble. The result is the production of huge amounts of fragmental volcanic debris. The famous "black sand" beaches of Hawaii were created virtually instantaneously by the violent interaction between hot lava and sea water. On the other hand, recent observations made from deep-diving submersibles have shown that some submarine eruptions produce flows and other volcanic structures remarkable similar to those formed on land. ...
That would be Ultramafic magma because Ultramafic magma has the lowest silica content so Iron and magnesium fills that gap
Magma is a mixture of molten or semi-molten rock that are found beneath the surface of the earth. Iron rich magma contains iron.
Magma rich in iron and magnesium is described as mafic.
In the past the term basic was used but this is now obsolete.
Basaltic lava.
mafic
Mafic
Igneous rocks that are dense and dark-colored are called basaltic rocks. They are formed from magma that is rich in iron and magnesium and poor in silica content.
Dark, mafic rock is relatively rich in iron and magnesium.
In Bowen's reaction series, feldspar minerals go through a continuous change of composition, while iron-magnesium groups have an abrupt change of mineral types. When magma cools, the feldspars that form are calcium-rich. As cooling continues, the feldspars react with magma and the feldspar composition changes. The result is a zoned crystal with sodium-rich outer layers and calcium-rich core. For iron-magnesium minerals, when magma starts cooling, a mineral begins to crystallize. However, when the magma temperature drops, a whole new mineral begins to form. The previously formed minerals reacts with the magma and is converted into the new mineral.
The mineral Olivine is a series between two end members, fayalite and forsterite. Fayalite is the iron rich member while forsterite is the magnesium rich member.
Mafic and ultramafic minerals, high in magnesium and iron.
They are rich in magnesium and iron.
Igneous rocks that are dense and dark-colored are called basaltic rocks. They are formed from magma that is rich in iron and magnesium and poor in silica content.
Those that are rich in iron and magnesium.
basaltic
Dark, mafic rock is relatively rich in iron and magnesium.
Dark, mafic rock is relatively rich in iron and magnesium.
Iron rich magma is something or other which is in a volcano or earthquake. Dont trust this website it isnt good as you can see
Olivine is the first mineral to crystallize as the mineral first to crystallize is the last to melt.
In Bowen's reaction series, feldspar minerals go through a continuous change of composition, while iron-magnesium groups have an abrupt change of mineral types. When magma cools, the feldspars that form are calcium-rich. As cooling continues, the feldspars react with magma and the feldspar composition changes. The result is a zoned crystal with sodium-rich outer layers and calcium-rich core. For iron-magnesium minerals, when magma starts cooling, a mineral begins to crystallize. However, when the magma temperature drops, a whole new mineral begins to form. The previously formed minerals reacts with the magma and is converted into the new mineral.
no its the least silica rich of granitic and andesitic magma.
Thin, easy flowing lava is usually rich in iron and magnesium. Thick, slow moving lava is usually rich in silica.
It is rich in iron and magnesium