Iterative thermodynamic modelling—Part 1: A theoretical scoring technique and a computer program ( Bingo‐Antidote )
Publisher DOI
Abstract
This paper introduces the software solution Bingo‐Antidote for thermodynamic calculations at equilibrium based on iterative thermodynamic models. It describes a hybrid strategy combining the strength of Gibbs energy minimization (GEM) and inverse thermobarometry models based on the comparison between the modelled and observed mineral assemblage, modes and compositions. The overall technique relies on quantitative compositional maps acquired by electron probe micro‐analyser for obtaining a mutually consistent set of observed data such as bulk rock and mineral compositions. Thus it offers the opportunity to investigate metamorphic rocks on a microscale. The scoring part Bingo integrates three statistical model quality factors urn:x-wiley:02634929:media:jmg12538:jmg12538-math-0001 for the assemblage, urn:x-wiley:02634929:media:jmg12538:jmg12538-math-0002 for the mineral modes, urn:x-wiley:02634929:media:jmg12538:jmg12538-math-0003 for the mineral compositions combined in a global evaluation criterion urn:x-wiley:02634929:media:jmg12538:jmg12538-math-0004 that quantifies how the model reproduces the observations for the investigated volume. The input parameters of GEM affecting the model quality such as pressure, temperature and eventually some components of the bulk composition (e.g. the molar amount of hydrogen, carbon or oxygen) or activity variables of fluids and gases (e.g. urn:x-wiley:02634929:media:jmg12538:jmg12538-math-0005, urn:x-wiley:02634929:media:jmg12538:jmg12538-math-0006, f(O2)) can be optimized by inversion in Antidote using several mapping stages followed by a direct search optimization. Examples of iterative models based on compositional maps processed with Bingo‐Antidote demonstrate the utility of the program. In contrast to the qualitative interpretation of phase diagrams, the inversion maximizes the benefits of GEM and permits the derivation of statistically ‘optimal’ pressure–temperature conditions for well‐equilibrated samples. In addition, Bingo‐Antidote opens new avenues for petrological investigations such as the generation of chemical potential landscape maps.
Date Issued
2020-06-09
Publication Type
Article
Subject(s)
Language(s)
en
Author(s)
Duesterhoeft, Erik |
Additional Credits
Journal
Journal of metamorphic geology
Publisher
Blackwell Scientific Publications
ISSN
0263-4929
Access(Rights)
open.access