Assessing trace element (dis)equilibrium and the application of single element thermometers in metamorphic rocks

Alicia M. Cruz-Uribe*, Maureen D. Feineman, Thomas Zack, Dorrit E. Jacob

*Corresponding author for this work

Research output: Contribution to journalReview article

11 Citations (Scopus)

Abstract

Empirical and experimental calibration of single element solubility thermometers, such as Zr-in-rutile, Zr-in-titanite, Ti-in-zircon, and Ti-in-quartz, within the past 13 years has greatly expanded our ability to assess the pressure and temperature conditions of individual minerals associated with specific textures in metamorphic rocks. Combined with advances in in situ techniques for analyzing trace concentrations, this has led to an increase in the combined use of single element thermometers, geochronometers, and isotope ratios, often simultaneously, in metamorphic minerals. Here we review the calibration and application of single element thermometers at the pressure and temperature conditions of interest in metamorphic rocks. We discuss to what extent accessory phase equilibrium and trace element equilibrium are attained in metamorphic systems, and the thermodynamic and kinetic framework within which trace element equilibrium is assessed. As an example, we present a comprehensive study of trace element distribution during rutile replacement by titanite in rocks that experienced high-temperature amphibolite-facies overprinting and those that underwent low-temperature blueschist-facies overprinting from a variety of subduction-related terranes worldwide. We find that trace element distributions approach equilibrium partition coefficients in rocks from amphibolite-facies overprinted terranes, whereas trace element distributions do not approach equilibrium in rocks that experienced blueschist-facies overprinting. We caution that single element thermometers that rely upon slow-diffusing high field strength elements should not be applied to rocks equilibrated at <600 °C unless attainment of trace element equilibrium can be demonstrated.

Original languageEnglish
Pages (from-to)1-15
Number of pages15
JournalLithos
Volume314-315
DOIs
Publication statusPublished - Aug 2018
Externally publishedYes

Keywords

  • Trace elements
  • Thermobarometry
  • Zr-in-rutile
  • Zr-in-titanite
  • Ti-in-zircon
  • Ti-in-quartz
  • Kinetics
  • Metamorphism

Fingerprint Dive into the research topics of 'Assessing trace element (dis)equilibrium and the application of single element thermometers in metamorphic rocks'. Together they form a unique fingerprint.

Cite this