The Effects of the Concentration of Olivine Xenocrysts on the Viscosity of Kimberlite Melts: Experimental Evidence
- 31 Downloads
The study of viscosity in sub-liquidus heterogeneous media, which includes kimberlite magma at the pressures and temperatures that prevail in the mantle, is an urgent task. We have conducted experiments in the serpentine–olivine, serpentine–CaCO3‒olivine, and native kimberlite–olivine systems at a pressure of 4 GPa and temperatures of 1400‒1600°С in a BARS high-pressure device using the technique of a falling Pt pellet. The samples were examined after experiments to find fine-grained chilled mass of crystals where the Pt pellet was observed at the time of chilling. The concentration of the solid phase was varied in the experiments between 10 and 50 wt %. We showed that when 50 wt % of olivine grains has been introduced, it was not possible to detect the motion of the Pt pellet, while when the concentration of olivine xenocrysts reached 10 wt %, the Pt pellet very rapidly descended to the bottom of the reaction volume. Viscosity was calculated using the Stokes method. We found that the viscosity of a homogeneous kimberlite melt at 4 GPa and 1600°С is below 2 Pa s, with the viscosity of a melt that contained up to 10 wt % of the solid phase being approximately constant. A kimberlite melt that contained 30 wt % of the solid phase had a viscosity on the order of 100 Pa s, while with 50 wt % of the solid phase the relative viscosity of an ultrabasic system increased to reach values over 1000 Pa s.
Unable to display preview. Download preview PDF.
- Brey, G.P. and Ryabchikov, I.D., Carbon dioxide in strongly silica undersaturated melts and origin of kimberlite magmas, N. Jarb. Mineral. Monatsh., 1994, vol. 10, pp. 449–463.Google Scholar
- Chepurov, A.I., Sonin, V.M., Surkov, N.V., et al., The project of experimental station of synchrotron radiation in VEPP-4M4 for research at high pressures and high temperatures on the multiple anvil apparatus BARS, Nuclear Instruments and Methods in Physics Research A, 2009, vol. 603, pp. 105–107.CrossRefGoogle Scholar
- Chepurov, A.I., Fedorov, I.I., and Sonin, V.M., Experimental studies of diamond formation at high PTparameters (supplement to the model for natural diamond formation), Geol. Geofiz., 1998, vol. 39, no. 2, pp. 234–244.Google Scholar
- Dreibus, G., Brey, G.P., and Girnis, A.V., The role of carbon dioxide in the generation and emplacement of kimberlite magmas: New experimental data on CO2 solubility, in Extended Abstracts 6th International Kimberlite Conference, 1995, pp. 80–82.Google Scholar
- Girnis, A.V., Bulatov, B.K., and Brey, G.P., Transition of kimberlite melts into carbonatite melts at mantle parameters: experimental study, Petrology, 2005, vol. 13(1), pp. 3–8.Google Scholar
- Hess, K.U. and Dingwell, D.G., Viscosities of hydrous leucogranitic melts: A non-Arrhenian model, American Mineralogist, 1996, vol. 81, pp. 1297–1300.Google Scholar
- Moss, S., Russell, J.K., Brett, R.C., and Andrews, G.D.M., Spatial and temporal evolution of kimberlite magma at A154N, Diavik, Northwest Territories, Canada, Lithos, 2009, vol. 112, pp. 541–552.Google Scholar
- Persikov, E.S., The viscosity of magmatic liquids: experiment, generalized patterns. A model for calculation and prediction, Applications, Advances in Physical Chemistry, 1991, vol. 9, pp. 1–4.Google Scholar
- Persikov, E.S. and Bukhtiyarov, P.G., The effect of dissolved water on the time-dependent viscosity of kimberlite and basaltic magmas during their origination, evolution, and ascent from mantle to crust, Eksperimental’naya Geokhimiya, 2014, vol. 2, no. 2, pp. 236–240.Google Scholar
- Price, S.E., Russell, J.K., and Kopylova, M.G., Primitive magma from the Jericho Pipe, N. W. T., Canada: Constrains on primary kimberlite melt chemistry, J. Petrology, 2000, vol. 41, pp. 789–808.Google Scholar
- Sobolev, N.V., Sobolev, A.V., Tomilenko, A.A., et al., Paragenesis and complex zoning of olivine macrocrysts from unaltered kimberlite of the Udachnaya-East pipe, Yakutia: relationship with the kimberlite formation conditions and evolution, Russ. Geol. Geophys., 2015, vol. 56, nos. 1-2, pp. 260–279.CrossRefGoogle Scholar