1/21
Modal classification of gabbroic rocks based on proportions of plag, ol, opx, cpx, and hbl. leuco- and mela- may be used as adjectives to denote light and dark colored repsectively. a) Gabbroic rocks enriched in plag, px, and ol b) Gabbroic rocks enriched in plag, opx, and cpx c) Gabbroic rocks enriched in plag, px, and hbl
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Figure 3
Modal classification of gabbroic rocks based on proportions of plag, ol, opx, cpx, and hbl. leuco- and mela- may be used as adjectives to denote light and dark colored respectively.
a) Gabbroic rocks enriched in plag, px, and ol
b) Gabbroic rocks enriched in plag, opx, and cpx
c) Gabbroic rocks enriched in plag, px, and hbl
Anorthosite
(abc) It contains >90% Plagioclase
Leuco-
adjective used for light colored gabbroic rocks that contain 65-90% Plagioclase
Gabbroids
Group of gabbroic rocks with 35-65% Plagioclase
Mela-
adjective used for dark colored gabbroic rocks that contain 10-35% Plagioclase
Ultramafic rocks
They contain <10% plagioclase
Gabbro, Gabbronorite, Norite
(a) They contain 10-90% Plagioclase, >90% Pyroxene, and <10% Olivine
Troctolite
(a) It contains 35-65% Plagioclase, <10% Pyroxene, and >90% Olivine
Plagioclase-bearing ultramafic rocks
(a) It contains Pyroxene, Olivine, and <10% Plagioclase
Olivine gabbro, Olivine gabbronorite, Olivine norite
(a) They contain Pyroxene, Olivine, and 10-35% Plagioclase
Norite
(b) It contains Plagioclase, >95% Orthopyroxene, and <5% Clinopyroxene
Gabbro
(b) It contains Plagioclase, >95% Clinopyroxene, and <5% Orthopyroxene
Gabbronorite
(b) It contains Plagioclase, 50% Orthopyroxene, and 50% Clinopyroxene
Cpx norite
(b) It contains 50-95% Orthopyroxene, and 5-50% Clinopyroxene
Opx norite
(b) It contains 5-50% Orthopyroxene, and 50-95% Clinopyroxene
Plagioclase-bearing pyroxenite
(b) It contains opx, cpx, and <10% Plagioclase
Horblende gabbro
c) It contains 35-65% Plagioclase, >90% Hornblende, <10% Pyroxene
Px Hbl gabbro, Px Hbl gabbronorite, Px Hbl norite
c) They contain Pyroxene, Hornblende, and 10-35% Plagioclase
Horblende pyroxenite
c) It contains <10% Plagioclase, 10-50% Hornblende, and 50-90% Pyroxene
Pyroxene hornblendite
c) It contains <10% Plagioclase, 50-90% Hornblende, and 10-50% Pyroxene
Plagioclase-bearing pyroxenite
c) It contains <10% Plagioclase, >90% Pyroxene, and <10% Hornblende
Plagioclase-bearing hornblendite
c) It contains <10% Plagioclase, >90% Hornblende, and <10% Pyroxene