TASMiddlemost {GCDkit}R Documentation

Middlemost's modification of TAS diagram

Description

Assigns data for Middlemost's modification of the TAS diagram into Figaro template (list 'sheet') and appropriate values into 'x.data' and 'y.data'.

Usage

TASMiddlemostVolc()

TASMiddlemostPlut()

Details

Middlemost's variation of classic IUGS-recommended TAS diagram, originally proposed by Le Bas et al. (1986). Boundaries of foidite, phonolite, trachyte, trachydacite and rhyolite fields are defined, as inferred from the phase relations in the TAS system. Moreover, the trachyte + trachydacite field is split into trachyte and trachydacite fields, silexite and sodalitite + nephelinolith + leucitolith fields are defined.

TASMiddlemostPlut.png

The same diagram layout is applied also to plutonic rocks as follows:

plutonic rocks volcanic rocks
Peridotgabbro Picrobasalt
Gabbro Basalt
Gabbroic Diorite Basaltic Andesite
Diorite Andesite
Granodiorite Dacite
Granite Rhyolite
Quartzolite Silexite
Monzogabbro Trachybasalt
Monzodiorite basaltic Trachyandesite
Monzonite Trachyandesite
Quartzmonzonite Trachydacite
Syenite Trachyte
Foid Gabbro Tephrite
Foid Monzodiorite Phonotephrite
Foid Monzosyenite Tephriphonolite
Foid Syenite Phonolite
Foidolite Foidite
Tawite/Urtite/Italite sodalitite/nephelinolith/leucitolith

TASMiddlemostVolc.png

Value

sheet

list with Figaro Style Sheet data

x.data

SiO2 weight percent

y.data

Na2O+K2O weight percent

Warning

Note that, unlike in the standard TAS plot, the diagram is based on standard analyses (i.e. it is not recalculated on the volatile-free basis).

Author(s)

Vojtěch Erban, erban@sopky.cz

References

Le Bas MJ, Le Maitre RW, Streckeisen A & Zanettin B (1986) A chemical classification of volcanic rocks based on the total alkali-silica diagram. J Petrology 27: 745-750

Middlemost EAK (1994) Naming materials in the magma/igneous rock system. Earth Sci Rev 37: 215-224 doi: 10.1016/0012-8252(94)90029-9

See Also

classify TAS Cox figaro plotDiagram

Examples

    data(atacazo) 
    accessVar("atacazo")

    # To plot data stored in WR or its subset (menu Classification)
    plotDiagram("TASMiddlemostVolc", FALSE)
    # or
    plotDiagram("TASMiddlemostPlut", FALSE)

    # To Classify data stored in WR (Groups by diagram)
    classify("TASMiddlemostVolc")
    # or
    classify("TASMiddlemostPlut")

[Package GCDkit version 6.1 Index]