Debon {GCDkit}R Documentation

BA and PQ diagrams (Debon + Le Fort 1983)

Description

Assigns data for Debon & Le Fort's B-A and P-Q diagrams into Figaro template (list 'sheet') and appropriate values into 'x.data' and 'y.data'.

Usage

DebonBA()
DebonPQ()

Details

The B-A diagram as proposed by Debon and Le Fort (1983) defines six sectors (I - VI), reflecting alumina balance of samples. Following minerals are characteristic for individual sectors:

DebonBA.png

I Peraluminous domain muscovite > biotite
II biotite > muscovite
III biotite (+- minor amphibole)
IV Metaluminous domain biotite, amphibole, +- pyroxene
V clinopyroxene, +- amphibole, +-biotite
VI unusual mineral associations (carbonatites ...)

Layout of the P-Q diagram of the same authors corresponds to cationic proportions of quartz, K-feldspar and plagioclase.

DebonPQ.png

Abbreviations used as classification output represent following rocks groups:

label plutonic rocks volcanic rocks
go gabbro, diorite, anorthosite basalt, andesite, kenningite
mzgo monzogabbro, monzodiorite latibasalt, latiandesite
mz monzonite latite
s syenite trachyte
dq qtz diorite,qtz gabbro,qtz anorthosite qtz andesite,qtz basalt
mzdq qtz monzodiorite,qtz monzogabbro qtz latiandesite,qtz latibasalt
mzq quartz monzonite quartz latite
sq quartz syenite quartz trachyte
to tonalite, trondhjemite dacite
gd granodiorite, granogabbro rhyodacite
ad adamellite dellenite
gr granite rhyolite

Parameters for the diagram are calculated by the function 'DebonCalc'. All of them are based on millications (1000 gram-atoms per 100 grams).

P = K - (Na + Ca)

Q = Si / 3 - (K + Na + 2 * Ca / 3)

A = Al - (K + Na + 2 Ca)

B = Fe + Mg + Ti

Note that the diagrams B-A and P-Q are recommended as complementary, i.e. resulting names should be used in conjunction (granite II etc.). For details, see Debon & Le Fort (1983) or (1988).

Value

sheet

list with Figaro Style Sheet data

x.data

P or B value. See details.

y.data

Q or A value. See details.

Author(s)

Vojtech Erban, vojtech.erban@geology.cz

& Vojtech Janousek, vojtech.janousek@geology.cz

References

Debon F & Le Fort P (1983) A chemical-mineralogical classification of common plutonic rocks and associations. Trans Roy Soc Edinb; Earth Sci 73: 135-149

Debon F & Le Fort P (1988) A cationic classification of common plutonic rocks and their magmatic associations: principles, method, applications. Bull. Mineral 111: 493-511

See Also

classify figaro plotDiagram DebonCalc


[Package GCDkit version 4.0 Index]