typ e of igneous rocks

7/28/2019 typ e of igneous Rocks

1/21


2/21

Hypocrystalline crystals + glass

glassPlane light

X polarized light

Holocrystalline 100% crystals


3/21

0 5 10 mm

Fine-grained (


4/21

1mm

1mm1mm

Equigranular Seriate/Hiatal

Porphyritic

Plagioclase Porphyritic or Plag-phyric


5/21

Subhedral AnhedralEuhedral


6/21

Subpoikilitic PoikililticAmeboidal

Oikocryst Chadacyrst


7/21

Embayed Skeletal

Spinifex DendriticRadial


8/21

Intergranular Subophitic Ophitic


9/21

Intersertal Pyroclastic

glass

olivine

Philip Farquharson, 2004www-odp.tamu.edu/
http://www-odp.tamu.edu/publications/192_IR/chap_03/c3_f45.htmhttp://www-odp.tamu.edu/publications/192_IR/chap_03/c3_f45.htm


10/21

Foliation alignment of elongate minerals in a common plane

Qualifiers: Non-foliated random orientation of elongate minerals

Poorly foliated less than 50% aligned within 10 of common plane

Moderately foliated 50-75% aligned

Well foliated - > 75% aligned


11/21

Trachytoid alignment in fine-grainedvolcanic rocks

Radiate


12/21

Micrographic/GranophyricSutured Symplectitic


13/21

Corona

Biotite on Oxide Hornblende on Orthopyroxene Clinopyroxene on Olivine


14/21

Rapakivi - Alkali Feldsparmantled by PlagioclaseFeldspar

Peritectic Reaction Rim

Ol+melt = Opx


15/21

Exsolution in

InvertedPigeonite

< Blebby

Lamellar >

Linked Exsolution between Inverted


16/21

Linked Exsolution between InvertedPigeonite (IP) and Augite (Cpx)

IP

IPBio

Feox

Cpx

Perthite Na-plagioclaseexsolved from K-feldspar


17/21

Oxide Needles in Plagioclase

Oxide Exsolution and Epitaxial Biotite

in Augite rimming Olivine


18/21

PlagioclaseSymplectite

Pl>CaPl+Opx

OlivineSymplectite

Ol>Opx+Mt


19/21

Simple Twin (in Cpx)

Polysynthetic Twinning

(Albite Twinning in Pl)


20/21

Textural and Modal Layeringin Gabbro

Flow banding in Rhyolite


21/21

Amygdules in Basalt

typ e of igneous rocks

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