The measured and predicted pH are then subject to change due to possible mineral precipitation and equilibration with atmospheric CO2(g) at room temperature.
To ensure full equilibration of minerals and the specific chelator, pre-washing was maintained in EDTA-2Na·2H2O for 2.5 h with agitation during the first 30 min [42], in 2,2'-bipyridyl for 2 h with continuous agitation, and in deionized H2O for 48 h without agitation.
Being component of most fluid composition controlling minerals (alumino-silicates), correct aluminum concentrations are necessary to calculate reliable equilibration temperatures for those minerals (Table 2).
Magnesium phases are excluded intentionally, since dilution of geothermal fluids with superficial, Mg-rich waters will significantly bias reservoir temperature estimations, by overestimating equilibration temperatures for magnesium minerals.
These lamellae result from the exsolution of a separate pyroxene phase from a host grain due to subsolidus re-equilibration (that occurs while the mineral is in the solid state) during slow cooling.
The chemical homogeneity of minerals suggests a high degree of thermal equilibration of particle RB-QD04-0042.
The observation of pores that are partially or completely filled with secondary minerals in otherwise unaltered rock raises the question of pore connectivity and how these minerals were formed, i.e., by slow equilibration with the basaltic rock in a closed pore or by hydrothermal alteration due to mass transport in a connected pore space.
Based on the interval concept, we present here a methodology for data reconciliation and mass balance equilibration which is a very classical problem in mineral and chemical engineering.
For a given volumetric fluid flow rate per unit area, each of these so-called pore water exchange cycles can be associated with a certain equilibration time, which in addition allows to calculate kinetic constraints for mineral dissolution/precipitation (though this functionality was not used in the present study).
By calculating the equilibration temperature of a large number of (reservoir) rock forming minerals, multicomponent geothermometry provides a more statistical approach of determining in situ temperatures.
