Igneous Rock Flashcards
(37 cards)
Light colored rock that is high in silica
Felcic
Acidic rock
Felsic rock
Gray colored
Ex: andesite and diorite
Intermediate
Dark colored
Silica and alkalis is less
Mafic
Basic rock
Mafic rock
Very dark colored
Highest density
Quartz is absent
Ultramafic
Fine grain
Fast cooling at the surface
Aphanitic
Course grain
Slow cooling
Phanitic
Large crystal embedded on the small mineral
Porphyritic
Wholly glassy texture
Holohyaline
Partially crystalline and glassy
Merocrystalline
Wholly crystalline
Holocrystalline
Minerals are completely bounded by crystal faces
Eurheral
Idiomorphic
Eutheral
Xenomorphic
Anhedral
Crystal faces are absenr
Anhedral
Partly bounded by crystal faces
Subhedral
Plutonic rock
Intrusive
-Formed under great pressure at high temperature
-There is presence of volatile
Plutonic
Extrusive rock
Volcanic
Solidifies under low pressure and in absence of volatiles
Volcanic / extrusive
-spongey
- develop due to the exsolution and entrapment of gas bubbles
Vesicular structure
Deposits of surface water subsequently fills up vesicles
Amygdaloidal
Numerous parallel polygonal prismatic columns bundheld together
Columnar structure