minComp {GCDkit} | R Documentation |
These functions calculate chemical compositions (in wt.% of oxides) based on mineral's formula(e).
minComp(n.at,oxides=major) plComp(An=0) olComp(Fo=1) idealMineralCompositions(my.mins=NULL)
n.at |
numeric: named vector with numbers of individual atoms |
oxides |
numeric: names of oxides to be returned |
An |
numeric: anorthite mass proportion(s), 0-1 |
Fo |
numeric: forsterite mass proportion(s), 0-1 |
my.mins |
character: vector with names of desired minerals |
The function minComp
takes two arguments. The first is
a named vector n.at
containing numbers of atoms per formula unit,
such as that produced by the function formula2vector
.
The second contains names of the desired oxide names.
NB that trivalent iron in the formula is to be denoted as 'FeIII'.
The functions plComp
and olComp
are front ends
calculating the chemical compositions of plagioclase or olivine for the
respective molar proportions of anorthite (An) and forsterite (Fo) end-members
(0 to 1).
The function idealMineralCompositions
calculates chemical
compositions (in wt. % of oxides) of the selected rock-forming minerals.
If none are specified upon the function's call, they can be selected from
a list (GUI).
Their ideal mineral formulae are based on (slightly modified) database of
Le Maitre (1982, Appendix 12).
This table with alphabetic list of ideal mineral molecules is stored,
together with originally calculated molecular weights,
in the file
'mineral_formulae.data
'.
A numeric matrix with calculated major-element compositions.
Vojtěch Janoušek, vojtech.janousek@geology.cz
Le Maitre RW (1982) Numerical Petrology. Developments in Petrology 8. Elsevier, Amsterdam, pp 1-281
# Albite z<-formula2vector("NaAlSi3O8") # Number of individual atoms pfu minComp(z,c("SiO2","Al2O3","Na2O")) # chemical composition in wt. % # Magnetite z<-formula2vector("FeFeIII2O4") minComp(z) # chemical composition in wt. % # Plagioclase of given An (0-1) plComp(0.5) plComp(seq(0,1,0.1)) # Olivine of given Fo 0-1 olComp(0.25) olComp(seq(0,1,0.1)) # Andradite idealMineralCompositions("Andradite") # Cancrinite idealMineralCompositions("Cancrinite") # Assorted minerals from Le Maitre's database which.mins<-c("Fluorite","Halite","Magnetite","Quartz","Orthoclase", "Albite","Anorthite","Andalusite") out<-idealMineralCompositions(which.mins) out<-data.frame(out) print(out[order(out$SiO2),]) # Sort the output by increasing silica