texture of igneous rocks in thin section
Post on 14-Feb-2017
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Hypocrystalline – crystals + glass
glassPlane light
X polarized light
Holocrystalline – 100% crystals
0 5 10 mm
Fine-grained (<1 mm)
Medium-grained (1-5 mm)
Coarse-grained (5-30 mm)
Aphanitic
Phaneritic
Intersertal Pyroclastic
glass
olivine
Philip Farquharson, 2004 www-odp.tamu.edu/
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 “
Linked Exsolution between Inverted Pigeonite (IP) and Augite (Cpx)
IP
IPBio
Feox
Cpx
Perthite – Na-plagioclase exsolved from K-feldspar
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