Dear Ajay Kumar,

3 approaches have been used to establish such geothermometers. The first consists of empirical calibrations, which were proposed to directly link the chlorite composition to the temperature. Most of these calibrations relied on variations in the tetrahedral Al content (Cathelineau & Nieva, 1985; Kranidiotis & McLean, 1987; Cathelineau, 1988; Hillier & Velde, 1991; Jowett, 1991; Zang & Fyfe, 1995), mirrored by Si counter-variation. The second approach is based on thermodynamic databases (e.g., Vidal et al., 2001, 2005, 2006; Lanari et al., 2014) and takes into account the non-ideality of the solid solution and the P effect. The third approach, which can be referred to as semiempirical, considers the chlorite þ quartz equilibrium and uses ratios of end-member activities to link chlorite composition to temperature through the equilibrium constant K (Walshe, 1986; Inoue et al., 2009; Bourdelle et al., 2013; Lanari et al., 2014). The Cathelineau (1988) geothermometer was used in an interesting paper published in 2011:

https://www.geothermal-energy.org/pdf/IGAstandard/NZGW/2011/55.pdf

Hope this helps! Best regards

Johannes

Dear Ajay Kumar,

as regards your question about most recent empirical chlorite geothermometers in use, please see:

https://www.researchgate.net/publication/257143654_A_new_chlorite_geothermometer_for_diagenetic_to_low-grade_metamorphic_conditions

Best of success!

Johannes

Article A new chlorite geothermometer for diagenetic to low-grade me...

Hi Ajay Kumar

There is a more recent paper:

"Low-temperature chlorite geothermometry: a graphical representation based

on a T–R2þ–Si diagram"

FRANCK BOURDELLE and MICHEL CATHELINEAU,  2015

Eur. J. Mineral.

2015, 27, 617–626