Amphibole and biotite of melanocratic rocks from the Ural granitic massifs: composition, relationship, petrogenetic consequences

Research subject. The article discusses the features of the relationship between biotite and amphibole on the example of magmatogene melanocratic rocks from a number of granitoid massifs of the Urals. These rocks form xenoliths and synplutonic intrusions of the calc-alkaline series of normal alkalinity: gornblenditam, gabbro, diorite, quartz diorite. They are composed of amphibole, acidic or middle plagioclase, in a subordinated quanitity they contain clinopyroxene, biotite, potassium feldspar, quartz.

Materials and methods. The composition of the minerals of melanocratic rocks was determined on a JSM-6990LV electron microscope with an EDC-adapter of INCA Energy 450 X-Max 80 in the Geoanalytical Center of the IGG Ural Branch of the Russian Academy of Sciences.

Results and conclusions. Wide variations in amphibole compositions and narrow biotite variations caused by exchange processes between the mineral and postmagmatic fluid are shown. The phenomenon of replacement of early magmatic amphibole with biotite is substantiated by the presence of a gap in the crystallization temperatures of minerals, indicating a lack of physicochemical equilibrium between them. Their structural relationships confirm the development of biotite as a result of the replacement of amphibole in accordance with the competent and incompetent phase boundaries. In the first case, the structural packets of biotite are embedded along the silicon-oxygen chains of amphibole, which is expressed in the parallelism of the (001) plane of biotite with the (100), (110) planes of amphibole. In the second case, the development of biotite occurs irregularly, inheriting the system of cracks in amphibole. The distribution of Mg/Fe between biotite and early magmatic amphibole was studied, showing that the magnesia value of biotite is higher than that of amphibole replaced by it. Inverse ratios of magnesia value occur between biotite and post-magmatic amphibole. The equality of the magnesia values of both minerals may reflect the conditions of subsolidus equilibration of the compositions. The problem of choosing amphibole compositions for calculating the PTparameters of the formation of massifs in the Earth crust is considered.

1. Ague J.J. (1989) The distribution of Fe and Mg between biotite and amphibole in granitic rocks: Effects of temperature, pressure and amphibole composition. Geochem. J., 23, 279-293.

2. Angiboust S., Harlov D. (2017) Ilmenite breakdown and rutile-titanite stability in metagranitoids: Natural observations and experimental results. Amer. Miner., 102, 1696-1708.

3. Barclay J., Carmichael I.S.E. (2004) A hornblende basalt from Western Mexico: Water-saturated phase relations constrain a pressure–temperature window of eruptibility. J. Petrol., 45(3), 485-506.

4. Borodina N.S., Fershtater G.B., Votyakov S.L. (1999) The oxidation ratio of iron in coexisting biotite and hornblende from granitic and metamorphic rocks. Geokhimiya, (6), 658-664. (In Russian)

5. Brimhall G.H., Agee C., Stoffregen R. (1985) The hydrothermal conversion of hornblende to biotite. Can. Miner., 23, 369-379.

6. Castro A., Stephens W.E. (1992) Amphibole-rich polycrystalline clots in calc-alkaline granitic rocks and their enclaves. Can. Miner., 30, l093-1112.

7. Choudhuri A. (1974) Distribution of Fe and Mg in Actinolite, Hornblende and Biotite in Some Precambrian Metagreywackes from Guyana, South America. Contrib. Mineral. Petrol., 44, 45-55.

8. Conrad W.K., Nicholls I.A., Wall V.J. (1988) Watersaturated and undersaturated melting of metaluminous and peraluminous crustal compositions at 10 kb: Evidence for the origin of silicic magmas in the Taupo volcanic zone, New Zealand, and other occurrences. J. Petrol., 29(4), 765-803.

9. de Albuquerque C.A.R. (1974) Geochmistry of actinolitic hornblende from tonalitic rocks, Northern Portugal. Geochim. Cosmochim. Acta, 38, 789-803.

10. Gorbatschev R. (1970) Distribution of Tetrahedral A1 and Si in Coexisting Biotite and Ca-Amphibole. Contrib. Mineral. Petrol., 28, 251-258.

11. Féménias O., Mercier J.C.C., Nkono C., Diot H., Berza T., Tatu M., Demaiffe D. (2006) Calcic amphibole growth and compositions in calc-alkaline magmas: Evidence from the Motru Dike Swarm (Southern Carpathians, Romania). Amer. Miner., 91, 73-81.

12. Ferrow E.A., Baginski B.W. (1998) Chloritisation of hornblende and biotite: a HRTEM study. Acta Geol. Polonica, 48(1), 107-113.

13. Fershtater G.B. (1987) Petrologiya glavnykh intruzivnykh associatsii [Petrology of the main intrusive associations]. Moscow, Nauka Publ., 230 p. (In Russian)

14. Fershtater G.B. (2013) Paleozoiskii intruzivnyi magmatizm Srednego i Yuzhnogo Urala [Paleozoic intrusive magmatism of the Middle and Southern Urals]. Ekaterinburg, UrB RAS, 365 p. (In Russian)

15. Fershtater G.B., Borodina N.S. (1975) Petrologiya magmaticheskikh granitoidov na primere Urala [Petrology of magmatic granitoids (on the example of the Urals)]. Moscow, Nauka Publ., 288 p. (In Russian)

16. Fershtater G.B., Borodina N.S., Chashchukhina V.A. (1978) Ferrofacies of granitoids. Geokhimiya, (2), 147-160. (In Russian)

17. Gray W., Smith R.K. (2010) Mineral Chemistry of the Tuolumne Intrusive Suite: Evidence for Disequilibrium and Implications for Estimated Magmatic Intensive Variables. Abstract V23B-2446 presented at 2010 Fall Meeting, AGU, San Francisco, Calif., 13-17 Dec.

18. Hawthorne F.C., Oberti R., Harlow G.E., Maresch W.V., Martin R.F., Schumacher J.C., Welch M.D. (2012) Nomenclature of the amphibole supergroup. Amer. Miner., 97, 2031-2048.

19. Henry D.J., Guidotti C.V., Thomson J.A. (2005) The Ti-saturation surface for low-to-medium pressure metapelitic biotites: Implications for geothermometry and Ti-substitution mechanisms. Amer. Miner., 90(2-3), 316-328.

20. Hietanen A. (1971) Distribution of Elements in BiotiteHornblende Pairs and in an OrthopyroxeneClinopyroxene Pair from Zoned Plutons, Northern Sierra Nevada, California. Contrib. Mineral. Petrol., 30, 161176.

21. Holland T., Blundy J. (1994). Non-ideal interactions in calcic amphiboles and their bearing on amphibole-plagioclase thermometry. Contrib. Mineral. Petrol., 116, 433-447.

22. Johannes W., Holtz F. (1996) Petrogenesis and Experimental Petrology of Granitic Rocks. Springer, 335 p.

23. Kallistov G.A. (2011) Petrologiya granitoidov Chelyabinskogo massiva. Dis. … kand. geol.-min. nauk [Petrology of granitoids of the Chelyabinsk Massif. Cand. geol. and min. sci. diss.]. Ekaterinburg, IGG UrB RAS Publ., 188 p. (In Russian)

24. Kanisawa S. (1972) Coexisting biotites and hornblendes from some granitic rocks in southem Kitakami Mountains, Japan. J. Japan. Assoc. Miner. Petrol. Econ. Geol., 67, 332-344.

25. Kuroda Y., Suzuoki T., Matsuo S., Kanisawa S. (1974) D/H fractionation of coexisting biotite and hornblende in some granitic rock masses. J. Japan. Assoc. Miner. Petrol. Econ. Geol., 69, 95-102.

26. Liou J.G., Zhang R., Ernst W.G., Liu J., McLimans R. (1998) Mineral paragenesis in the Pianpaludo eclogitis body, Gruppo di Voltri, western Ligurian Alps. Schweizerische Mineralogische und Petrographische Mitteilungen, 78, 317-335.

27. Lo´pez S., Castro A., Garcı´a-Casco A. (2005) Production of granodiorite melt by interaction between hydrous mafic magma and tonalitic crust. Experimental constraints and implications for the generation of Archaean TTG complexes. Lithos, 79, 229-250.

28. Mason G.H. (1985) The mineralogy and textures of the Coastal batholith, Peru. Eds W.S. Pitcher et al. Magmatism at a plate edge, the Peruvian Andes. Wiley, N.Y., 156-166.

29. Mutch E.J.F., Blundy J.D., Tattitch B.C., Cooper F.J., Brooker R.A. (2016) An experimental study of amphibole stability in low-pressure granitic magmas and a revised Al-in-hornblende geobarometer. Contrib. Mineral. Petrol., 171, 85. DOI: 10.1007/s00410-016-1298-9

30. Naney M.T. (1983) Phase equilibria of rock-forming ferromagnesian silicates in granitic systems. Amer. J. Sci., 283, 993-1033.

31. Oliveira M.A., Dall’Agnol R., Scaillet B. (2010) Petrological Constraints on Crystallization Conditions of Mesoarchean Sanukitoid Rocks, Southeastern Amazonian Craton, Brazil. J. Petrol., 51(10), 2121-2148.

32. Orogennyi granitoidnyi magmatizm Urala [Orogenic granitoid magmatism of the Urals]. (1994) (Ed. G.B. Fershtater). Miass, IGG UrB RAS, 250 p. (In Russian)

33. Pribavkin S.V. (2000) Petrologiya osnovnykh porod v granitoidakh Shabrovskogo i Shartashskogo massivov. Dis. … kand. geol.-min. nauk [Petrology of the mafic rocks in granitoids of Shabry and Shartash massifs. Cand. geol. and min. sci. diss.). Ekaterinburg, IGG UrB RAS, 244 p. (In Russian)

34. Puchkov V.N. (2010) Geologiya Urala i Priural’ya (aktual’nye voprosy stratigrafii, tektoniki, geodinamiki i metallogenii) [Geology of the Urals and the Suburalian areas (actual issues of stratigraphy, tectonics, geodynamics and metallogeny)]. Ufa, DizainPoligrafServis Publ., 280 p. (In Russian)

35. Schmidt M.W. (1993) Phase relations and compositions in tonalite as a function of pressure: an experimental study at 650 °C. Amer. J. Sci., 293, 1011-1060.

36. Shagalov E.S. (2002) Petrologiya i geokhimiya porod Syrostansko-Turgoyakskoi gruppy granitoidnykh massivov, Yuzhnyi Ural. Dis. … kand. geol.-min. nauk [Petrology and geochemistry of rocks of Syrostan-Turgoyak group of granitoid massifs, South Ural. Cand. geol. and min. sci. diss.]. Ekaterinburg, IGG UrB RAS, 188 p. (In Russian)

37. Sharp T.G., Buseck P.R. (1988) Prograde versus retrograde chlorite-amphibole intergrowths in a calc-silicate rock. Amer. Miner., 73, 1292-1301.

38. Speer J.A. (1987) Evolution of magmatic AFM The hornblende Libertv Hill. Amer. Miner., 72, 863-878.

39. Tanaka H. (1975) Magnesium-iron distribution in coexisting biotite and hornblende from granitic rocks. J. Japan. Assoc. Mineral. Petrol. Econ. Geol., 70, 118-124.

40. Vyhnal C.R., McSween H.Y., Speer J.A. (1991) Hornblende chemistry in southern Appalachian granitoids: Implications for aluminum hornblende thermobarometry and magmatic epidote stability. Amer. Miner., 76, 176-188.

41. Zin’kova E.A. (1997) Geokhimiya, istoriya formirovaniya i petrogenezis Verkhisetskogo granitoidnogo batolita, Srednii Ural. Dis. … kand. geol.-min. nauk [Geochemistry, formation history and petrogenesis of the Verkhisetsk granitoid batholith, Middle Urals. Cand. geol. and min. sci. diss.]. Ekaterinburg, IGG UrB RAS Publ., 182 p. (In Russian)