The stability of sphene; experimental redetermination and geologic implications

Details The stability of sphene; experimental redetermination and geologic implications The stability of sphene; experimental redetermination and geologic implications

Feb 1977

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1977gecoa..41..279h&link_type=abstract

Geochimica et Cosmochimica Acta, vol. 41, Issue 2, pp.279-280

Other

14

Scientific paper

Hydrothermal experiments on the reaction: rutile + calcite + QUARTZ = sphene + CO 2 , suggest equilibrium at: P fluid = 2 kbar , 500 ± 5° C , X CO 2 = 0.5 ± 0.006; P fluid = 3.45 kbar , 535 ± 10° C , X CO 2 = 0.5 ± 0.006; P fluid = 5 kbar , <580° C , X CO 2 = 0.5 ± 0.006; P fluid = 5 kbar , <635° C , X CO 2 = 0.97 ± 0.035. The resultant stability field of sphene is much larger than that suggested by and (1967). Calculation of the reaction in P - T space directly from free energy data indicates a discrepancy in r of about 1.5 kcal/gfw when compared to our experimental data. In addition, P - T extrapolation of the reaction using thermochemical data disagrees with the constraints of the two experimental brackets, indicating possible errors in the entropy of one or more solid phases and/or in CO 2 free energy data. The combination of these experimental results with published data on reactions involving additional minerals allows the recognition of sphene and/or rutile-bearing assemblages which can be used as indicators of P - T - X CO 2 conditions at various grades of metamorphism. In particular, mineral assemblages useful in delimiting P - T - X CO 2 conditions are: muscovite-sphene (H 2 O-rich fluids), diopside-rutile-quartz (high temperatures or a CO 2 -rich fluid at low temperatures), epidote-rutile-quartz (low temperatures, H 2 O-rich conditions), prehnite-rutile (very low temperatures, very H 2 O-rich conditions).

Affiliated with

Also associated with

No associations

Rating

The stability of sphene; experimental redetermination and geologic implications 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 The stability of sphene; experimental redetermination and geologic implications, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The stability of sphene; experimental redetermination and geologic implications will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-799700