Syenogranite

Syenogranite is a fine to coarse grained intrusive igneous rock of the same general composition as granite.The feldspar component of syenogranite is predominantly orthoclase.
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.

englishsyenogranite.jpg

QAPF Diagram Syenogranite field in blue





Bibliography



• Eric A.K.Middlemost (1985): Magmas and Magmatic Rocks. Longman, London
• Ron H. Vernon (2004): A pratical guide to rock microstructure. Cambridge editore
• K.G.Cox, J.D.Bell & R.J Pankhurst (1979): The interpretetion of igneous rocks. George Allen&Unwin editori.
• David Shelley (1983): Igneous and metamorphic rocks under the microscope. Campman & Hall editori


Photo
sienogranito66(2).jpg

Orthoclase, plagioclase and clinopyroxene (high interference coloros). XPL image, 2x (Field of view = 7mm)
sienogranito66(3).jpg

Orthoclase, plagioclase and clinopyroxene (high interference coloros). XPL image, 2x (Field of view = 7mm)
sienogranito66(4).jpg

Orthoclase, plagioclase and clinopyroxene (high interference coloros). XPL image, 2x (Field of view = 7mm)
sienogranito66(5).jpg

Orthoclase, plagioclase and clinopyroxene (high interference coloros). XPL image, 2x (Field of view = 7mm)
sienogranito66(6).jpg

Orthoclase, plagioclase and clinopyroxene (high interference coloros). XPL image, 2x (Field of view = 7mm)
sienogranito66(7).jpg

Orthoclase, plagioclase and clinopyroxene (high interference coloros). XPL image, 2x (Field of view = 7mm)