What is trachyte rock?

What is trachyte rock?

trachyte, light-coloured, very fine-grained extrusive igneous rock that is composed chiefly of alkali feldspar with minor amounts of dark-coloured minerals such as biotite, amphibole, or pyroxene. Compositionally, trachyte is the volcanic equivalent of the plutonic (intrusive) rock syenite.

Is quartz a volcanic rock?

Quartz is an igneous rock made out of molecules of silicon and oxygen atoms held together in a crystal pattern. All of the silica and oxygen that make quartz came originally from the insides of stars, and it shot out of the stars when the stars exploded as supernovas.

What type of rock is Peralkaline trachyte?

A subgroup of the Feldspar Group, poor in calcium, and mostly rich in potassium. A petrological term for Albite-Anorthite Series.

Where is trachyte formed?

Trachytes are well represented among the Cenozoic volcanic rocks of Europe. In Britain they occur in Skye as lava flows and as dikes or intrusions, but they are much more common on the continent of Europe, as in the Rhine district and the Eifel, also in Auvergne, Bohemia and the Euganean Hills.

What type of rock is a quartz?

Quartz is a defining constituent of granite and other felsic igneous rocks. It is very common in sedimentary rocks such as sandstone and shale. It is a common constituent of schist, gneiss, quartzite and other metamorphic rocks.

Is trachyte a basalt?

Trachyte is the usual silica-rich end member of the alkaline magma series, in which alkaline basaltic magma experiences fractional crystallization while still underground.

What is Peralkaline granite?

Aplites are equigranular granitic rocks with little mafic component occurring in veins or dykes. Granophyres are granitic rocks in which quartz and feldspar has a granophyric intergrowth.

Is Trachyte porphyry intrusive or extrusive?

Trachyte is an extrusive rock, belonging to the alkali series of intermediate volcanic rocks.

What type of rock is trachyte?

Trachyte is a extrusive igneous rock that light coloured is composed mostly of alkali feldspar with minor amount of dark coloured minerals such as biotite, amphibole, or pyroxene. Trachyte is the volcanic equivalent of rock Syenite.

Is quartz rare in trachyte crystals?

Quartz is rare in trachyte, but tridymite (which likewise consists of silica) is not uncommon. It is rarely in crystals large enough to be visible without the aid of the microscope, but in thin sections it may appear as small hexagonal plates, which overlap and form dense aggregates, like a mosaic or like the tiles on a roof.

What is a trachytic texture?

Trachytic texture occurs in alkaline rich rocks; therefore, the vitreous mass of the rocks has a relatively low viscosity. Trachytic texture is especially characteristic of trachytes and rocks similar to trachytes.

What is the difference between syenite and trachyte?

See TAS diagram below to see how these rock types differ in their chemistry. Trachyte is a volcanic equivalent of syenite. Syenite is a feldspar-rich plutonic rock which is similar to granite but lacks or contains very little quartz.