Fandom

Geology Wiki

Syenogranite

519pages on
this wiki
Add New Page
Talk0 Share

Syenogranite is a fine to coarse grained intrusive igneous rock of the same general composition as granite. They are characteristically felsic.

The feldspar component of syenogranite is predominantly alkaline in character (usually orthoclase). For example, the syenogranite in the Salmon Mountains in Idaho is pink to tan and composed of 45–55% alkali feldspar, 15–20% plagioclase, 15–20% quartz, 5–8% biotite, 3–5% hornblende, and accessory magnetite (Evans and Green, 2003).

Syenogranite is similar to syenite, however the major difference is its higher content of quartz (15-25%) usually at the expense of some alkali feldspar (45-50%), the domination of biotite over hornblende and the presence of muscovite and rutile as additional accessories in the syenogranite. Some syenogranite contain rare idiomorphic amphibole (Fe-hornblende and Fe-edenite), biotite (annite 25%-35%), plagioclase (An3), along with K-feldspar and quartz. (Mafti, 2001).

In the Sao Jose do Campestre Massif in Brazil, the syenogranite is a coarse-grained rock composed of microcline, quartz, hornblende, and rare clinopyroxene, together with allanite, as essential minerals (Benjamin et al., 1998).

See alsoEdit

ReferencesEdit

  • Bley, Benjamin, Peter Christian Hackspacher, Elton Luizdantas, and William Randall Van Schmus. (1998) "Archean Accretion in the Sao Jose do Campestre Massif, Borborema Province, Northeast Brazil." Revista Brasileirade Geociencias, Vol. 28 [1]
  • Karl V. Evans and Gregory N. Green (2003) “Geological Map of the Salmon National Forest and Vicinity, East-Central Idaho.” U.S. Department of the Interior, U. S. Geological Survey.[2]
  • Mafti, Mohammed Rashad H. (2001) "Age, Geochemistry and Origin of the Peraluminous A-Type Granitoids of the Ablah-Shuwas Pluton, Ablah Graben Arabian Shield." Faculty of Earth Sciences, King Abdulaziz University, Acta Mineralogica-Petrographica, Vol. 42, pp. 5–20.[3]Template:Petrology-stub

Ad blocker interference detected!


Wikia is a free-to-use site that makes money from advertising. We have a modified experience for viewers using ad blockers

Wikia is not accessible if you’ve made further modifications. Remove the custom ad blocker rule(s) and the page will load as expected.