Simple Lithology

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acidic igneous rock
broader acidic igneous material
narrower acidic igneous rock
igneous rock
narrower acidic igneous rock
definition Igneous rock with more than 63 percent SiO2. more like this
example siliceous igneous rock more like this
narrower dacite
broader acidic igneous rock
granitoid
broader acidic igneous rock
narrower alkali feldspar granite
quartz rich igneous rock
broader acidic igneous rock
rhyolitoid
broader acidic igneous rock
narrower alkali feldspar rhyolite
source after LeMaitre et al. 2002 more like this
type
Resource
Concept
in scheme simplelithology
alkali olivine basalt
definition Alkali olivine basalt is silica-undersaturated, characterized by the absence of orthopyroxene, absence of quartz, presence of olivine, and typically contains some feldspathoid mineral, alkali feldspar or phlogopite in the groundmass. Feldspar phenocrysts typically are labradorite to andesine in composition. Augite is rich in titanium compared to augite in tholeiitic basalt. Alkali olivine basalt is relatively rich in sodium. more like this
note The definition of tholeiite and alkali basalt here are more prescriptive than those found in most reference authorities. This is to actually provide some descriptive criteria to allow assignment of rocks on a hand sample basis to the tholeiite or alkali basalt categories if detailed petrographic or chemical data are available. more like this
source http://en.wikipedia.org/wiki/Basalt; Carmichael, I.S. Turner, F.J., Verhoogen, John, 1974, Igneous petrology: New York, McGraw HIll Book Co., p.42-43. more like this
type
Resource
Concept
broader basalt
narrower alkali olivine basalt
in scheme simplelithology
alkali feldspar granite
definition Granitic rock that has a plagioclase to total feldspar ratio less than 0.1. QAPF field 2. more like this
example
alaskite more like this
peralkaline granite more like this
source LeMaitre et al. 2002 more like this
type
Resource
Concept
broader granitoid
in scheme simplelithology
alkali feldspar rhyolite
definition Rhyolitoid in which the ratio of plagioclase to total feldspar is less than 0.1. QAPF field 2. more like this
example
alkali feldspar liparite more like this
peralkaline rhyolite more like this
source LeMaitre et al. 2002 more like this
type
Resource
Concept
broader rhyolitoid
in scheme simplelithology
alkali feldspar syenite
definition Alkali feldspar syenitic rock that contains 0-5 percent quartz and no feldspathoid in the QAPF fraction. QAPF field 6. more like this
source LeMaitre et al. 2002 more like this
type
Resource
Concept
broader alkali feldspar syenitic rock
in scheme simplelithology
alkali feldspar syenitic rock
definition Syenitoid with a plagioclase to total feldspar ratio of less than 0.1. QAPF fields 6, 6*, and 6'. more like this
narrower alkali feldspar syenite
foid bearing alkali feldspar syenite
broader alkali feldspar syenitic rock
quartz alkali feldspar syenite
broader alkali feldspar syenitic rock
source LeMaitre et al. 2002 more like this
type
Resource
Concept
broader syenitoid
narrower alkali feldspar syenitic rock
in scheme simplelithology
alkali feldspar trachyte
definition Trachytoid that has a plagioclase to total feldspar ratio less than 0.1, between 0 and 5 percent quartz in the QAPF fraction, and no feldspathoid minerals. QAPF field 6. more like this
source LeMaitre et al. 2002 more like this
type
Resource
Concept
broader alkali feldspar trachytic rock
in scheme simplelithology
alkali feldspar trachytic rock
definition Trachytoid that has a plagioclase to total feldspar ratio less than 0.1. QAPF fields 6, 6', and 6*. more like this
narrower alkali feldspar trachyte
foid bearing alkali feldspar trachyte
broader alkali feldspar trachytic rock
quartz alkali feldspar trachyte
broader alkali feldspar trachytic rock
source LeMaitre et al. 2002 more like this
type
Resource
Concept
broader trachytoid
narrower alkali feldspar trachytic rock
in scheme simplelithology
amphibolite
definition Metamorphic rock mainly consisting of green, brown or black amphibole and plagioclase (including albite), which combined form 75 percent or more of the rock, and both of which are present as major constituents. The amphibole constitutes 50 percent or more of the total mafic constituents and is present in an amount of 30 percent or more; other common minerals include quartz, clinopyroxene, garnet, epidote-group minerals, biotite, titanite and scapolite. more like this
source Coutinho et al. 2007, IUGS SCMR chapter 8 (http://www.bgs.ac.uk/SCMR/) more like this
type
Resource
Concept
broader metamorphic rock
narrower amphibolite
in scheme simplelithology
andesite
broader fine grained igneous rock
narrower andesite
intermediate composition igneous rock
narrower andesite
definition Fine-grained igneous rock with less than 20 percent quartz and less than 10 percent feldspathoid minerals in the QAPF fraction, in which the ratio of plagioclase to total feldspar is greater 0.65. Includes rocks defined modally in QAPF fields 9 and 10 or chemically in TAS field O2 as andesite. Basalt and andesite, which share the same QAPF fields, are distinguished chemically based on silica content, with basalt defined to contain less than 52 weight percent silica. If chemical data are not available, the color index is used to distinguish the categories, with basalt defined to contain greater than 35 percent mafic minerals by volume or greater than 40 percent mafic minerals by weight. Typically consists of plagioclase (frequently zoned from labradorite to oligoclase), pyroxene, hornblende and/or biotite. Fine grained equivalent of dioritic rock. more like this
example
basaltic andesite more like this
leuco-basalt more like this
mela-andesite more like this
note Note the mela-andesite and leuco-basalt categories are not recommended in this system. If chemical analytical data are available to constrain the silica content, the basalt or andesite category should be used. more like this
source after LeMaitre et al. 2002 more like this
type
Resource
Concept
in scheme simplelithology
narrower boninite
broader andesite