Thermochemistry of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6

Details Thermochemistry of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6 Thermochemistry of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6

Jan 1979

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1979gecoa..43...55n&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 43, Issue 1, pp.55-60

Physics

17

Scientific paper

Enthalpies of solution of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6 have been measured in a melt of composition Pb 2 B 2 O 5 at 970 K. Most of the measurements were made on samples crystallized at 1600°-1700°C and 30 kbar pressure, which covered the range 0-78 mole per cent Mg 2 Si 2 O 6 , and whose X-ray patterns could be satisfactorily indexed on the diopside (C2/c) structure. For the reaction: Mg 2 Si 2 O 6 - Mg 2 Si 2 O 6 enstatite diopside the present data, in conjunction with previous and new measurements on Mg 2 Si 2 O 6 enstatite, determine H ° ~ 2 kcal and W H (regular solution parameter) ~ 7 kcal. These values are in good agreement with those deduced by and (1975) from a study of high temperature, high pressure phase equilibrium data under the assumption that the excess entropy of mixing is small, but, in light of the recent theoretical treatment of and (1977, Phys. Chem. Min. 1 , 109-127), the meanings of these parameters may be ambiguous. Heat of solution measurements on Ca-rich binary diopsides made by annealing glasses at 1358°C in air gave slighter higher values than the higher temperature high pressure samples. This may be evidence for some (Ca, Mg) disorder of the sort postulated by and (1977, Phys. Chem. Min . 1 , 109-127), although no differences in heat of solution dependent on synthesis temperature in the range 1350°-1700°C could be found in stoichiometric CaMgSi 2 O 6 .

Affiliated with

Also associated with

No associations

Rating

Thermochemistry of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Thermochemistry of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermochemistry of synthetic clinopyroxenes on the join CaMgSi 2 O 6 -Mg 2 Si 2 O 6 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1142122