Valid garnet-biotite thermometer: A comparative study

Abstract

The abundance of garnet-biotite pair in a wide range of rocks mainly from upper green schist to granulite facies has made it one of the most widely used pairs for estimation of temperature at which once rocks equilibrated. In last four decades, more than 20 thermometer models of garnet-biotite pair have been proposed. To find the suitability of models, twenty-one thermometers formulated by a number of scholars since 1976 is considered. 27 sample data of granulites from the global literature were collected and processed through the “Gt-Bio.EXE” software. We conclude that four models are the most valid and reliable of these kinds of thermometers: Perchuk and Lavrente’va (1983); Thompson (1976); Ferry and Spear (1978) and Holdaway and Lee (1977).

An Evaluation of Garnet – Clinopyroxene Geothermometer

“…To test the validity and applicability of garnet-clinopyroxene thermometry, we have collated 89 samples from the literature all over the world (supplementary sheet attached). Samples were selected to fit the following criteria [3,4]…”

“…Several thermobarometric studies have been undertaken over the years, which led to the development of a range of thermometers and barometers, such as garnetclinopyroxene thermometry [1,2], garnet-orthopyroxene thermometry [3], garnetbiotite thermometry [4,5], garnet-hornblende thermometry [6], garnet cordierite thermometry [7], and two pyroxene thermometry [8].…”

Applicability of garnet-cordierite (Gt-Crd) geothermometer

“…To test the validity and applicability of garentcordierite (Gt-Crd) thermometry, we have collected 70 samples (60 of granulites and 10 of UHT/UHP) from the literature all over the world. Selection of samples fit the following criteria (Wu and Cheng, 2006;Thomas et al, 2018;Thomas and Rana, 2019):…”

“…The validity of a thermometer is a prerequisite in the study of metamorphism. Several thermobarometric studies had been undertaken in the past few years, which led to the development of a range of thermometers and barometers, such as garnet-biotite thermometer (Wu and Cheng, 2006;Thomas and Rana, 2019), garnetclinopyroxene thermometer (Jahnson et al, 1983;Fu et al, 1998), garnet-orthopyroxene thermometer (Thomas et al, 2018).…”

Evaluation of two (opx-cpx) pyroxene Geothermometer

“…Several models for two pyroxene (Opx-Cpx) thermometers have been proposed in recent decades. Numerous thermobarometric studies undertaken over the last few decades led to the development of a range of thermometers and barometers, such as garnet-clinopyroxene thermometry (Johnson et al, 1983;Fu et al, 1998), garnet-orthopyroxene thermometry (Thomas et al, 2018), garnet -biotite thermometry (Thomas and Rana, 2019), garnet -cordierite thermometry , clinopyroxene is the basis of widely used geothermometers for deep-seated mantle rocks and high grade crustal terrains, mainly granulites and garnet peridotites. Its correct determination is thus crucial for estimating pressure temperature distributions in the earth's crust and mantle.…”