Latite

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Latite
Volcanic rock
Latit - Boxberg, Hocheifel.jpg
Photomicrograph of thin section of latite (in plane polarised light)
Photomicrograph of thin section of latite (in cross polarised light)

Latite is an igneous, volcanic rock, with aphanitic-aphyric to aphyric-porphyritic texture. Its mineral assemblage is usually alkali feldspar and plagioclase in approximately equal amounts. Quartz is less than five percent and is absent in a feldspathoid-bearing latite, and olivine is absent in a quartz-bearing latite. When quartz content is greater than five percent the rock is classified as quartz latite.[1] Biotite, hornblende, pyroxene and scarce olivine or quartz are common accessory minerals.

Rhomb porphyries are an unusual variety with gray-white porphyritic rhomb shaped phenocrysts embedded in a very fine grained red-brown matrix. The composition of rhomb porphyry places it in the trachyte - latite classification of the QAPF diagram.

Latite is found, for example, as lavas in Bulgaria[2] and as intrusive laccoliths and sills in South Dakota, USA.[3]


See also[edit]

References[edit]

  1. ^ Classification of Igneous Rocks
  2. ^ Georgiev, V. and Milovanov, P. (2001). "Volcanism in the Momchilgrad Volcanotectonic Depression". Comptes Rendus de l'Academie Bulgare des Sciences 54 (3): 63–66. Bibcode:2001CRABS..54c..63G.  Retrieved on 5 July 2015.
  3. ^ "Latitic Intrusive Rocks". USGS. Retrieved 5 July 2015.