doc-ext-functions.md

External Functions

XMapTools includes a set of external functions for calculating structural formulas, thermobarometry and other methods. Source code for all functions is available on the XMapTools GitHub repository.

Table of contents

• Structural formulas
• Thermobarometry and other methods
  • Map-mode
  • Multi-equilibrium

Structural formulas

The following structural formula functions are available in XMapTools. Each function calculates structural formulas and end-member proportions on a specified oxygen basis.

Aluminosilicate > AlSil. (SF, 5-Ox. basis)

XMapTools External Function: structural formula of aluminosilicates. Version without loop & all Fe as Fe₂O₃. 5 Oxygen-basis.

Amphibole > CaAmp (SF, 23-Ox. basis)

XMapTools External Function: structural formula of Ca-amphibole. Fe₂O₃ added as possible input. Ti ordered onto M2 (Raase 1974).

End-member	T1(4)	T2(2)	M2(2)	M13(2)	M4(2)	A(1)
Glaucophane (Gln)	Si₄	Si₄	Al,Al	Mg,Mg,Mg	Na,Na	V
Tremolite (Tr)	Si₄	Si₄	Mg,Mg	Mg,Mg,Mg	Ca,Ca	V
F-tremolite (Ftr)	Si₄	Si₄	Fe,Fe	Fe,Fe,Fe	Ca,Ca	V
Tschermakite (Ts)	Si₄	Si₂,Al₂	Al,Al	Mg,Mg,Mg	Ca,Ca	V
Pargasite (Prg)	Si₄	Si₂,Al₂	Mg,Al	Mg,Mg,Mg	Ca,Ca	Na

Other: Ti, Mn. 23 Oxygen-basis.

Amphibole > CaAmp_Fe3+ (SF, 23-Ox. basis)

XMapTools External Function: structural formula of Ca-amphibole with Fe³⁺ estimation. 23 Oxygen-basis. Not tested.

Biotite > Bt+ (SF, 11-Ox. basis)

XMapTools External Function: structural formula of biotite. Fe₂O₃ added as possible input. Ti assumed to be ordered onto M2, Al onto M1, Mn added (ordered onto M12).

End-member	T1(2)	T2(2)	M1(1)	M2(2)	A(1)
Phlogopite	Si,Si	Si,Al	Mg	Mg,Mg	K
Annite	Si,Si	Si,Al	Fe	Fe,Fe	K
Eastonite	Si,Si	Al,Al	Al	Mg,Mg	K
Siderophyllite	Si,Si	Al,Al	Al	Fe,Fe	K
Ti-biotite	Si,Si	Si,Al	Mg	Ti,Mg	K
Mn-biotite	Si,Si	Si,Al	Mn	Mn,Mn	K

11 Oxygen-basis.

Brucite > Brc (SF, 1-Ox. basis)

XMapTools External Function: structural formula of brucite. Version without loop & Fe₂O₃ as possible input. As₂O₃ is used instead of As₂O₅ in XMapTools 3.4.2. 1 Oxygen-basis.

Chlorite > Chl (SF, 14-Ox. basis)

XMapTools External Function: structural formula of chlorite. Ferri-sudoite added; Trincal & Lanari (2016) Clay Min. 51, 675–689. Fe₂O₃ added as possible input. 1 Input: XFe3 = Fe3/(Fe2+Fe3).

End-member	T1(2)	T2(2)	M1(1)	M2-M3(4)	M4(1)
Amesite (Ame)	Si,Si	Al,Al	Al	Mg₄	Al
Fe-Amesite (fAme)	Si,Si	Al,Al	Al	Fe₄	Al
Clinochlore (Clc)	Si,Si	Si,Al	Mg	Mg₄	Al
Daphnite (Dph)	Si,Si	Si,Al	Fe	Fe₄	Al
Sudoite (Sud)	Si,Si	Si,Al	V	Mg₂,Al₂	Al
FerriSudoite (fSud)	Si,Si	Si,Al	V	Mg₂,Fe₂	Al
AlfreeChl (afchl)	Si,Si	Si,Si	Mg	Mg₄	Mg

14 Oxygen-basis.

Chloritoid > Ctd (SF, 12-Ox. basis)

XMapTools External Function: structural formula of chloritoid. Version without loop & Fe₂O₃ as possible input.

End-member	T1(2)	T2(3)	M1(1)	M2(2)
Mg-chloritoid (Ctd)	Si,Si	Al₃	Al	Mg,Mg
Fe-chloritoid (fCtd)	Si,Si	Al₃	Al	Fe,Fe
Mn-chloritoid (mCtd)	Si,Si	Al₃	Al	Mn,Mn

12 Oxygen-basis.

Chromite > Chr (SF, 32-Ox. basis)

XMapTools External Function: structural formula of chromite. Version without loop & Fe₂O₃ as possible input. Fe³⁺ estimated using Droop (1987). 32 Oxygen-basis. Not tested in this version.

Clinopyroxene > Cpx (SF, 6-Ox. basis)

XMapTools External Function: structural formula of clinopyroxene. Version without loop & Fe₂O₃ as possible input.

End-member	T1(2)	M1(1)	M2(1)
Jadeite (Jd)	Si,Si	Al	Na
Diopside (Di)	Si,Si	Mg	Ca
Hedenbergite (Hd)	Si,Si	Fe	Ca
Ca-Tschermak (Cats)	Si,Al	Al	Ca

6 Oxygen-basis.

Clinopyroxene > Cpx_Fe3+ (SF, 6-Ox. basis)

XMapTools External Function: structural formula of clinopyroxene with Fe³⁺ estimation.

End-member	T1(2)	M1(1)	M2(1)
Jadeite (Jd)	Si,Si	Al	Na
Diopside (Di)	Si,Si	Mg	Ca
Hedenbergite (Hd)	Si,Si	Fe²	Ca
Ca-Tschermak (Cats)	Si,Al	Al	Ca
Acmite (Acm)	Si,Si	Fe³	Na

6 Oxygen-basis.

Cordierite > Crd (SF, 18-Ox. basis)

XMapTools External Function: structural formula of cordierite. Version without loop & Fe₂O₃ as possible input.

End-member	T1(2)	T2(3)	M1(2)
Mg-Cordierite (Crd)	Si₅	Al₄	Mg,Mg
Fe-Cordierite (fCrd)	Si₅	Al₄	Fe,Fe
Mn-Cordierite (mCrd)	Si₅	Al₄	Mn,Mn

18 Oxygen-basis.

Epidote > Ep (SF, 12.5-Ox. basis)

XMapTools External Function: structural formula of epidote. Version without loop & all iron as Fe³⁺.

End-member	T1(3)	M1(1)	M2(1)	M3(1)	A1(2)
Epidote (Ep)	Si₃	Al	Al	Fe	Ca,Ca
Fe-epidote (fEp)	Si₃	Fe	Al	Fe	Ca,Ca
Zoisite (Zo)	Si₃	Al	Al	Al	Ca,Ca
Mn-epidote (mEp)	Si₃	Al	Al	Mn	Ca,Ca

12.5 Oxygen-basis.

Feldspar > Fsp (SF, 8-Ox. basis)

XMapTools External Function: structural formula of feldspar. Version without loop & Fe₂O₃ as possible input.

End-member	T1(2)	T2(2)	M1(1)
Albite (Ab)	Si,Si	Si,Al	Na
Anorthite (An)	Si,Si	Al,Al	Ca
Sanidine (Sn)	Si,Si	Si,Al	K

8 Oxygen-basis.

Garnet > Grt (SF, 12-Ox. basis)

XMapTools External Function: structural formula of garnet. Version without loop & Fe₂O₃ as possible input.

End-member	X(3)	Y(2)	O/T(3)
Almandine (Alm)	Fe₃	Al₂	(SiO₄)₃
Pyrope (Prp)	Mg₃	Al₂	(SiO₄)₃
Grossular (Grs)	Ca₃	Al₂	(SiO₄)₃
Spessartine (Sps)	Mn₃	Al₂	(SiO₄)₃

12 Oxygen-basis.

Garnet > Grt_Fe3+ (SF, 12-Ox. basis)

XMapTools External Function: structural formula of garnet with Fe³⁺ estimation. Method of Droop (1987) implemented.

End-member	X(3)	Y(2)	O/T(3)
Almandine (Alm)	Fe₃	Al₂	(SiO₄)₃
Pyrope (Prp)	Mg₃	Al₂	(SiO₄)₃
Grossular (Grs)	Ca₃	Al₂	(SiO₄)₃
Spessartine (Sps)	Mn₃	Al₂	(SiO₄)₃
Andradite (And)	Ca₃	Fe₂	(SiO₄)₃

12 Oxygen-basis.

Ilmenite > Ilm (SF, 3-Ox. basis)

XMapTools External Function: structural formula of ilmenite. Approximation of Fe³⁺ and Fe²⁺; works fine with Ca-Na-K ignored.

End-member	Formula
Ilmenite (Ilm)	Fe(1)Ti(1)O(3)
Mn-Ilmenite (mIlm)	Mn(1)Ti(1)O(3)
Hematite (Hem)	Fe(2)O(3)

3 Oxygen-basis.

Magnetite > Mag (SF, 4-Ox./3-cat. basis)

XMapTools External Function: structural formula of magnetite. Version without loop & Fe₂O₃ as possible input. Normalized to 3 cations (assuming 4 oxygen). 4 Oxygen-basis.

Olivine > Ol (SF, 4-Ox. basis)

XMapTools External Function: structural formula of olivine. Version without loop & Fe₂O₃ as possible input.

End-member	Formula
Forsterite (Fo)	Mg(2)Si(1)O(4)
Fayalite (Fa)	Fe(2)Si(1)O(4)
Tephroite (Tep)	Mn(2)Si(1)O(4)

4 Oxygen-basis.

Orthopyroxene > Opx (SF, 3-Ox. basis)

XMapTools External Function: structural formula of orthopyroxene. Version without loop & Fe₂O₃ as possible input.

End-member	T1(1)	M1(1)
Enstatite (En)	Si₂	Mg₂
Ferrosilite (Fs)	Si₂	Fe₂
Tschermak-px (Mgts)	Si,Al	Al,Mg

3 Oxygen-basis.

Rutile > Rt (SF, 2-Ox. basis)

XMapTools External Function: structural formula of rutile. Version without loop & Fe₂O₃ as possible input. 2 Oxygen-basis.

Serpentine > Srp (SF, 14-Ox. basis)

XMapTools External Function: structural formula of serpentine. Number of oxygen changed from 14.5 to 14. Ratio Si/(Si+Fe+Mg) added. Version without loop & Fe₂O₃ as possible input. 14 Oxygen-basis.

Spinel > Spl (SF, 4-Ox. basis)

XMapTools External Function: structural formula of spinel. Version without loop & Fe₂O₃ as possible input. Fe³⁺ estimated using Droop (1987).

Al spinels (AlSpinel):

End-member	X(1)	Y(2)
Hercynite (Hc)	Fe	Al₂
Spinel (Spl)	Mg	Al₂
Galaxite (Glx)	Mn	Al₂
Gahnite (Ghn)	Zn	Al₂

Cr spinels (CrSpinel):

End-member	X(1)	Y(2)
Chromite (Chr)	Fe	Cr₂
Magnesiochromite (mChr)	Mg	Cr₂
Nichromite (Nic)	Ni	Cr₂

Fe spinels (FeSpinel):

End-member	X(1)	Y(2)
Magnesioferrite (Mfr)	Mg	Fe₂
Magnetite (Mag)	Fe	Fe₂
Ulvospinel (tSpl)	Ti	Fe₂
Jacobsite (Jac)	Mn	Fe₂
Franklinite (Frk)	Zn	Fe₂
Trevorite (Tre)	Ni	Fe₂

Olivine spinels (OlSpinel):

End-member	X(1)	Y(2)
Ringwoodite (Rwd)	Si	Mg₂

4 Oxygen-basis. Calculated assuming equipartition of Fe²⁺/Mg²⁺/Mn²⁺/Zn²⁺/Ni. Not tested.

Staurolite > St (SF, 22-Ox. basis)

XMapTools External Function: structural formula of staurolite. Version without loop & Fe₂O₃ as possible input.

End-member	Z(11)	Y(2)	X(4)
Staurolite (St)	Si(4)Al(7)	Al,Al	Fe₄
Mg-Staurolite (Mst)	Si(4)Al(7)	Al,Al	Mg₄
Mn-Staurolite (MnSt)	Si(4)Al(7)	Al,Al	Mn₄

24 Oxygen-basis.

White mica > Mica (SF, 11-Ox. basis)

XMapTools External Function: structural formula of white mica (generic). Version without loop & Fe₂O₃ as possible input.

End-member	T1(2)	T2(2)	M1(1)	M2(2)	A(1)
Celadonite-Mg (Cel)	Si,Si	Si,Si	V	Al,Mg	K
Celadonite-Fe (fCel)	Si,Si	Si,Si	V	Al,Fe	K
Muscovite (Ms)	Si,Si	Si,Al	V	Al,Al	K
Paragonite (Pg)	Si,Si	Si,Al	V	Al,Al	Na
Pyrophyllite (Prl)	Si,Si	Si,Si	V	Al,Al	V

Not considered: Biotite (Si,Si | Si,Al | MgFe | MgFeTi | K). 11 Oxygen-basis.

Thermobarometry and other methods

Function headers for thermobarometry and other methods. Source code is available on the XMapTools GitHub repository. Several functions are taken from the PTtoolbox package of Joshua Laughton.

Map-mode

Amphibole > T.Amp (all calibrations)

XMapTools External Function: amphibole thermobarometry. 23 Oxygen-basis.

Output variables:

• T_HB94: Holland & Blundy (1994) – no quartz
• T_HB94q: Holland & Blundy (1994) – with quartz

Biotite > T.Bt (all calibrations)

XMapTools External Function: biotite thermobarometry. 22 Oxygen-basis.

Output variables:

• T_W20: Wu & Chen (2015)
• T_H05: Henry et al. (2005)

Chlorite > T.Chl (all calibrations)

XMapTools External Function: chlorite thermometry (all calibrations). Fe₂O₃ added as possible input. 14 Oxygen-basis.

Output variables:

• T_L14_2: Lanari et al. (2014) Contrib. Miner. Petrol. 167:167–968 (LWV2)
• T_B13: Bourdelle et al. (2013) Contrib. Miner. Petrol. 165:723–735
• T_ZF95: Zang & Fyfe (1995) Miner. Depos. 30:30–38
• T_HV91: Hillier & Velde (1991) Clay Miner. 26:149–168
• T_J91: Jowett (1991) Program Abstr. 16:A62
• T_C88: Cathelineau (1988) Clay Miner. 23:471–485
• T_KM87: Kranidiotis & MacLean (1987) Econ. Geol. 82:1898–1911
• T_CN85: Cathelineau & Nieva (1985) Contrib. Miner. Petrol. 91:235–244

Monazite > Age.Mz (Montel 1996)

XMapTools External Function: monazite geochronology.

Output variables:

• Age_M96: Montel (1996)

Input variables: ThO₂, UO₂ and PbO in wt% (use the converter if your data were calibrated in a different format).

Quartz > T.Qz (all calibrations)

XMapTools External Function: quartz thermobarometry (all calibrations).

Output variables:

• T_WW06: Wark & Watson (2006)
• T_KO08: Kawasaki & Osanai (2008)
• T_T10: Thomas et al. (2010)
• T_HA12: Huang & Audétat (2012)
• T_O22: Osborne et al. (2022) CPM 177:31

Input variables: TiO₂ (wt%).

Rutile > T.Rt (all calibrations)

XMapTools External Function: rutile thermobarometry (all calibrations).

Output variables:

• T_Z04: Zack et al. (2004)
• T_W06: Watson et al. (2006)
• T_FW07: Ferry & Watson (2007), CMP 154:429–437
• T_T07: Tomkins et al. (2007)

Input variables: ZrO₂ (wt%).

Titanite > T.Ttn (all calibrations)

XMapTools External Function: titanite thermometry (all calibrations).

Output variables:

• T_H08: Hayden et al. (2008)

White mica > P.Phg (all calibrations)

XMapTools External Function: phengite barometry. 11 Oxygen-basis.

Output variables:

• P_MS87: Massone & Schreyer (1987)

Zircon > T.Zrn (all calibrations)

XMapTools External Function: zircon thermobarometry (all calibrations).

Output variables:

• T_W06: Watson et al. (2006)
• T_FW07: Ferry & Watson (2007), CMP 154:429–437

Multi-equilibrium

Amphibole > T.Grt-Hbl (all calibrations)

XMapTools External Function: Garnet-Hornblende thermometry. 12 Oxygen-basis for Garnet, 23 Oxygen-basis for Hornblende.

Output variables:

• T_GP84: Graham & Powell (1984)
• T_Per85: Perchuk et al. (1985)
• T_Pow85: Powell (1985)
• T_R00: Ravna (2000)

Biotite > T.Grt-Bt (all calibrations)

XMapTools External Function: Garnet-Biotite thermometry. 12 Oxygen-basis for Garnet, 11 Oxygen-basis for Biotite.

Output variables:

• T_T76: Thompson (1976)
• T_GA77: Goldman & Albee (1977)
• T_HL77: Holdaway & Lee (1977)
• T_FS78: Ferry & Spear (1978)
• T_HS82: Hodges & Spear (1982)
• T_PL83: Perchuk & Lavrent'eva (1983)
• T_GS84: Ganguly & Saxena (1984)
• T_IM85: Indares & Martignole (1985)
• T_P85: Perchuk et al. (1985)
• T_D91: Dasgupta et al. (1991)
• T_B92: Bhattacharya et al. (1992)

Chlorite > T.Grt-Chl (all calibrations)

XMapTools External Function: Garnet-Chlorite thermometry. 12 Oxygen-basis for Garnet, 14 Oxygen-basis for Chlorite.

Output variables:

• T_DH86: Dickenson & Hewitt (1986)
• T_G90: Grambling (1990)
• T_P91: Perchuk (1991)

Clinopyroxene > T.Grt-Cpx (all calibrations)

XMapTools External Function: Garnet-Clinopyroxene thermometry. 12 Oxygen-basis for Garnet, 6 Oxygen-basis for Clinopyroxene.

Output variables:

• T_MH72: Mysen & Heier (1972)
• T_RG74: Raheim & Green (1974)
• T_MG78: Mori & Green (1978)
• T_EG79: Ellis & Green (1979)
• T_S79: Saxena (1979)
• T_D80: Dahl (1980)
• T_P85: Powell (1985)
• T_K88: Krogh (1988)
• T_A94: Ai (1994)
• T_R00: Ravna (2000)
• T_N09: Nakamura (2009)

Cordierite > T.Grt-Crd (all calibrations)

XMapTools External Function: Garnet-Cordierite thermometry. 12 Oxygen-basis for Garnet, 18 Oxygen-basis for Cordierite.

Output variables:

• T_C71: Currie (1971)
• T_T76: Thompson (1976)
• T_HL77: Holdaway & Lee (1977)
• T_P85: Perchuk et al. (1985)
• T_B88: Bhattacharya et al. (1988)
• T_B93: Bhattacharya (1993)

Ilmenite > T.Grt-Ilm (all calibrations)

XMapTools External Function: Garnet-Ilmenite thermometry. 12 Oxygen-basis for Garnet, 3 Oxygen-basis for Ilmenite. Not tested.

Output variables:

• T_P87: Pownceby et al. (1987)
• T_P91: Pownceby et al. (1991)
• T_M10: Martin et al. (2010)

Orthopyroxene > T.Grt-Opx (all calibrations)

XMapTools External Function: Garnet-Orthopyroxene thermometry. 12 Oxygen-basis for Garnet, 6 Oxygen-basis for Orthopyroxene.

Output variables:

• T_MG78: Mori & Green (1978)
• T_D80: Dahl (1980)
• T_R83: Raith et al. (1983)
• T_H84: Harley (1984)
• T_LG84: Lee & Ganguly (1984)
• T_SB84: Sen & Bhattacharya (1984)
• T_P85: Perchuk et al. (1985)
• T_LG88: Lee & Ganguly (1988)
• T_AP89: Aranovich & Podlesskii (1989)
• T_PL90: Perchuk & Lavrente'va (1990)
• T_B91: Bhattacharya et al. (1991)

White Mica > T.Grt-Ph (all calibrations)

XMapTools External Function: Garnet-Phengite thermometry. 12 Oxygen-basis for Garnet, 11 Oxygen-basis for Phengite.

Output variables:

• T_KR88: Krogh & Raheim (1978)
• T_GH82: Green & Hellman (1982)
• T_HF88: Hynes & Forest (1988)
• T_W02: Wu et al. (2002)