This chapter reviews the development, calibration, and some applications of quadrilateral solution models based on pairwise interactions in the generalized point approximation. First introduced to the geologic community by Thompson (1969, 1970), this type of model has been applied to several mineral ...
Phase relations in the pyroxene quadrilateral at 980°C and 15 kbar (abstract) 来自 Semantic Scholar 喜欢 0 阅读量: 16 作者:DH Lindsley,HE King,AC Turnock,JE Grover 关键词: geothermal energy pyroxenes phase studies very high pressure very high temperature minerals oxygen compounds silicates ...
Transfer and exchange equilibria in a portion of the pyroxene quadrilateral as deduced from natural and experimental data Differences in the chemical composition of metamorphic and igneous pyroxene minerals may be attributed to a transfer reaction, which determines the Ca cont... Ralph,Kretz - 《Geoch...
A thermodynamic model for quadrilateral pyroxene solutions, is developed from the following assumptions: 1) Non-convergent cation-disorder of Fe and Mg occurs over the Ml and M2 sites; 2) Ca is partitioned completely into the M2 site; and 3) Clinopyroxenes unmix to a high-Ca plus low-Ca ...
To remedy this situation, this paper examines 658 Mossbauer spectra acquired from 64 synthetic samples covering the pyroxene quadrilateral in roughly 10 mol% increments, and determines their fundamental Mossbauer parameters as a function of composition. Results show variations in all the Mossbauer ...
Using published phase diagrams on the pyroxene quadrilateral, Gibbs free energy of formation of fictive orthohedenbergite has been calculated. Application of the ideally mixing fictive component model to computation of phase equilibria leads to the determination of compositions of coexisting Fe-Mg-Ca ...
The subsolidus trend for both Ca-rich and Ca-poor pyroxenes has been established, from the Mg-rich portion of the quadrilateral to the Hed-Fs join, together with the orientations of the tie-lines joining coexisting pyroxenes. For the Mg-rich Ca-poor pyroxenes, Brown's (1957) solidus ...
R. Kretz, “Transfer and Exchange Equilibria in a Portion of the Pyroxene Quadrilateral as Deduced from Natural and Experimental Data,” Geochim. Cosmoch. Acta. 46 , 411–421 (1982).Kretz, R (1982) Transfer and exchange equilibria in a portion of the pyroxene quadrilateral as deduced from ...
The model for the thermodynamic properties of multicomponent pyroxenes (Part I) is calibrated for ortho- and clinopyroxenes in the quadrilateral subsystem defined by the end-member components Mg 2 Si 2 O 6 , CaMgSi 2 O 6 , CaFeSi 2 O 6 , and Fe 2 Si 2 O 6 . This calibration ...
Electron-microprobe analyses of coexisting Ca-rich and Ca-poor pyroxenes from rocks of the Skaergaard intrusion indicate that their compositional relationships are controlled by two types of tie-line in the pyroxene quadrilateral. Solidus tie-lines join bulk compositions of pairs of pyroxenes that ...