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:

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. Acronyms 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 3.00 Index]