The low temperature phase behavior of the system H2O-NaCl-FeCl2 was examined using synthetic fluid inclusions. Experiments were conducted along the 5 wt% NaCl (relative to the total solution) pseudobinary, with FeCl2 concentrations varying from 2 to 33 wt%, and along the pseudobinary defined by mixing known amounts of FeCl2-4H2O with a 5 wt% NaCl solution, with final FeCl2 concentrations varying from 0 to 29 wt%. Synthetic fluid inclusions in quartz were prepared in cold-seal pressure vessels at 500 degrees C - 800 degrees C and 2 or 3 kilobars. The fO2 conditions were controlled by the Ni-NiO equilibrium curve. The liquid released from the capsule upon opening was initially colorless, but turned yellow-orange after contact with atmospheric O2. The clear color is characteristic of ferrous iron solutions, whereas the yellow-orange color is consistent with the presence of Fe3+ in solution. This color change suggested that the unopened capsules initially contained ferrous iron in solution, which oxidized to ferric iron when exposed to the atmosphere.
Borisenko (1977) reported a eutectic temperature of -37 degrees C for the system H2O-NaCl-FeCl2. In this study, it was not possible to verify this temperature due to the persistence of a metastable liquid down to liquid N2 temperatures (~-196 degrees C).
Final ice melting temperatures were obtained for concentrations less than 24 wt% FeCl2 and show a decrease in temperature with increase in FeCl2 concentration. For more concentrated solutions, final melting temperatures could not be obtained because the samples could not be frozen. / Master of Science
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/31155 |
| Date | 09 February 2000 |
| Creators | Baldassaro, Paige Marie |
| Contributors | Geological Sciences, Bodnar, Robert J., Rimstidt, J. Donald, Tracy, Robert J. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
| Relation | ETD.pdf |
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