Origin of potassium-bearing tourmalines of the Kumdy-Kolsky deposit (Kokchetav massif, Northern Kazakhstan): Study of Mineral inclusions

Research subject. Mineral inclusions in potassium-bearing tourmaline crystals of the Kumdy-Kol microdiamond deposit. Aim. To reconstruct PT conditions for the origin of potassium-bearing tourmalines. Materials and methods. Mineral analysis and element mapping were performed using an X-ray spectral microanalyzer. Raman spectroscopy was used to detect the C and SiO₂ polymorphs. Results. For the first time, diamond inclusions were identified in tourmalines with the potassium content ranging from 1.0 to 1.6 wt %. In addition, diamond-bearing zircon was detected in tourmaline crystals, with the K₂O content below the detection limit. Previously, diamond inclusions had been exclusively identified only within the most potassium-rich cores of tourmaline crystals, which were approved as a new end member referred to as maruyamaite. Similar to the previous studies, the Kfs inclusions were recognized in both marumaite crystals and tourmaline crystals, with a variable content of potassium. Conclusions. The obtained findings indicate that high-pressure conditions may not be necessary for the formation of potassium-rich tourmaline. The chemical composition of the fluid is most likely to be the main factor controlling the appearance of tourmalines with an unusual composition.

1. Angel R.J., Mazzucchelli M.L., Alvaro M., Nimis P., Nestola F. (2014) Geobarometry from host-inclusion systems: The role of elastic relaxation. Amer. Miner., 99, 2146-2149.

2. Berryman E.J., Wunder B., Wirth R., Rhede D., Schettler G., Franz G., Heinrich W. (2015) An experimental study on K and Na incorporation in dravitic tourmaline and insight into the origin of diamondiferous tourmaline from the Kokchetav Massif, Kazakhstan. Contrib. Mineral. Petrol., 169, 28. https://doi.org/10.1007/s00410-015-1116-9

3. Berryman E., Wunder B., Rhede D. (2014) Synthesis of K-dominant tourmaline. Amer. Miner., 99, 539-542.

4. Borghini A., Ferrero S., O'Brien P.J., Laurent O., Gunter C., Ziemann M.A. (2020) Cryptic metasomatic agent measured in situ in Variscan mantle rocks: Melt inclusions in garnet of eclogite, Granulitgebirge, Germany. Metamorphic Geol., 38, 207-234.

5. Chopin C. (1984) Coesite and pure pyrope in high-grade blueschists of Western Alps: a first record and some con-sequences. Contrib. Mineral. Petrol., 86, 107-118.

6. Chopin C., Sobolev N.V. (1995) Principal mineralogic indicators of UHP in crustal rocks. ultrahigh Pressure Metamorphism. (Ed. by R.G. Coleman, X. Wang). Cambridge, Cambridge University Press, 96-131.

7. Dobretsov N.L., Buslov M.M., Zhimulev F.I., Travin A.V., Zayachkovsky A.A. (2006) Vendian-Early Ordovician geodynamic evolution and model for exhumation of ultrahigh- and high-pressure rocks from the Kokchetav subduction-collision zone (Northern Kazakhstan). Russian Geol. Geophys., 47(4), 424-440 (translated from Geologiya i Geofizika, 47(4), 428-444).

8. Dobretsov N.L., Sobolev N.V., Shatsky V.S., Coleman R.G., Ernst W.G. (1995) Geotectonic evolution of diamondi-ferous paragneisses of the Kokchetav complex, Northern Kazakhstan - the geologic enigma of ultrahigh-pressure crustal rocks within Phanerozoic foldbelt. Island Arc, 4, 267-279.

9. Dobrzhinetskaya L.F., Braun T.V., Sheshkel G.G., Podkuiko Y.A. (1994) Geology and structure of diamond-bearing rocks of the Kokchetav massif, Kazakhstan. Tectonophysics, 233, 293-313.

10. Ferrero S., Angel R.J. (2018) Micropetrology: Are Inclusions Grains of Truth? J. Petrol., 59, 1671-1700.

11. Ferrero S., Bartoli O., Cesare B., Salvioli-Mariani E., Acosta-Vigil A., Cavallo A., Groppo C., Battiston S. (2012) Microstructures of melt inclusions in anatectic metasedimentary rocks. J. Metamorphic Geol., 30, 303-322.

12. Ferrero S., Ziemann M.A., Angel R.J., O'Brien P.J., Wunder B. (2015) Kumdykolite, kokchetavite, and cristobalite crystallized in nanogranites from felsic granulites, Orlica-Snieznik Dome (Bohemian Massif): not evidence for ultrahigh-pressure conditions. Contrib. Mineral. Petrol., 171, 3.

13. Hermann J., Green D.H. (2001) Experimental constraints on high pressure melting in subducted crust. Earth Planet. Sci. Lett., 188, 149-186.

14. Hwang S.L., Yui T.F., Chu H.T., Shen P., Liou J.G., Sobolev N.V. (2013) Oriented kokchetavite compound rods in clinopyroxene of Kokchetav ultrahigh-pressure rocks. J. Asian Earth Sci., 63, 56-69.

15. Hwang S.-L., Shen P., Chu H.-T., Yui T.-F., Liou J.G., Sobolev N.V. (2009) Kumdykolite, an orthorhombic polymorph of albite, from the Kokchetav ultrahigh-pressure massif, Kazakhstan. Europ. J. Miner., 21, 1325-1334.

16. Hwang S.-L., Shen P., Chu H.-T., Yui T.-F., Liou J.G., Sobolev N.V., Shatsky V.S. (2005) Crust-derived potassic fluid in metamorphic microdiamond. Earth Planet. Sci. Lett., 231, 295-306.

17. Hwang S.-L., Shen P., Chu H.-T., Yui T.-F., Liou J.G., So-bolev N.V., Zhang R.-Y., Shatsky V.S., Zayachkovsky A.A. (2004) Kokchetavite: a new potassium-feldspar polymorph from the Kokchetav ultrahigh-pressure terrane. Contrib. Mineral. Petrol., 148, 380-389.

18. Kanzaki M., Xue X., Amalberti J., Zhang Q. (2012) Raman and NMR spectroscopic characterization of high-pressure K-cymrite (KAlSi3O8<H2O) and its anhydrous form (kokchetavite). J. Mineral. Petrol. Sci., 107, 114-119.

19. Korsakov A.V., Hermann J. (2006) Silicate and carbonate melt inclusions associated with diamonds in deeply sub-ducted carbonate rocks. Earth Planet. Sci. Lett., 241, 104-118.

20. Korsakov A.V., Mikhailenko D.S., Zhang L., Xu Y.-G. (2023а) Inclusions of diamond crystals in the tourmaline of the schorluvite series: problems of genesis. J. Mining in-te, 261, 1-9 (translated from Zapiski Gornogo instituta, 261, 1-9). https://doi.org/10.31897/PMI.2023.18

21. Korsakov A.V., Rezvukhina O.V., Rezvukhin D.I., Greshnyakov E.D., Shur V.Y. (2020) Dumortierite and tourmaline from the Barchi-Kol diamond-bearing kyanite gneisses (Kokchetav massif): A Raman spectroscopic study and petrological implications. J. Raman Spectroscopy, 51, 1839-1848.

22. Korsakov A.V., Shatsky V.S., Sobolev N.V. (1998) The first finding of coesite in eclogites of the Kokchetav massif. Dokl. RAN, 360, 77-81. (In Russ.)

23. Korsakov A.V., Shatsky V.S., Sobolev N.V., Zayachkovsky A.A. (2002) Garnet-biotite-clinozoisite gneisses: a new type of diamondiferous metamorphic rocks of the Kokchetav massif. Europ. J. Miner., 14, 915-929.

24. Korsakov A.V., Theunissen K., Smirnova L.V. (2004) Inter-granular diamonds derived from partial melting of crustal rocks at ultrahigh-pressure metamorphic conditions. Terra Nova, 16, 146-151.

25. Korsakov A.V., Travin A.V., Yudin D.S., Marschall H.R. (2009) 40Ar/39Ar dating of tourmaline from metamorphic rocks of the Kokchetav massif, Kazakhstan. Dokl. Earth Sci., 424, 168-170 (translated from Dokl. RAN, 424, 531-533).

26. Korsakov A.V., Yudin D.S., Musiyachenko K.A., Demin S.P. (2023б) 40Ar/39Ar dating of maruyamaite (K-dominant tourmaline) from diamond-bearing metamorphic rocks from the Kokchetav massif. Geodynamics & Tectonophysics, 14(3). (In Russ.) https://doi.org/10.5800/GT-2023-14-3-0699

27. Korsakov A.V., Zhimulev E.I., Mikhailenko D.S., Demin S.P., Kozmenko O.A. (2015) Graphite pseudomorphs after diamonds: An experimental study of graphite mor-phology and the role of H2O in the graphitisation process. Lithos, 236-237, 16-26. https://doi.org/10.1016/j.lithos.2015.08.012

28. Lavrent'ev Yu.G., Karmanov N.S., Usova L.V. (2015) Electron probe microanalysis of minerals: Microanalyzer or scanning electron microscope? Russ. Geol. Geophys., 56, 1154-1161 (translated from Geologiya i Geofizika, 56, 1473-1482).

29. Lavrova L.D., Pechnikov V.A., Petrova M.A., Zayachkovsky A.A. (1996) Geology of diamondiferous Barchi-Kol area. Otech. Geologiya, (12), 20-27. (In Russ.)

30. Lavrova L.D., Pechnikov V.A., Pleshakov M.A., Nadajdina E.D., Shukolyukov Yu.A. (1999) A new genetic type of diamond deposit. Moscow, Nauch. mir Publ., 221 p. (In Russ.)

31. Letnikov F.A. (1983) Formation of diamonds in deep-seated tectonic zones. Dokl. AN SSSR, 271, 433-435. (In Russ.)

32. Lussier A., Ball N.A., Hawthorne F.C., Henry D.J., Shimizu R., Ogasawara Y., Ota T. (2016) Maruyamaite, K(MgAl2)(Al5Mg)Si6O18(BO33(OH)3O, a potassium-dominant tourmaline from the ultrahigh-pressure Kokchetav massif, northern Kazakhstan: Description and crystal structure. Amer. Miner., 101, 355-361.

33. Marschall H.R., Korsakov A.V., Luvizotto G.L., Nasdala L., Ludwig T. (2009) On the occurrence and boron isotopic composition of tourmaline in (ultra)high-pressure meta-morphic rocks. J. Geol. Soc., London, 166, 811-823.

34. Massonne H.-J., Bernhardt H.-J., Dettmar D., Kessler E., Medenbach O., Westphal T. (1998) Simple identification and quantification of microdiamonds in rock thinsections. Europ. J. Miner., 10, 497-504.

35. Mikhno A.O., Korsakov A.V. (2013) K2O prograde zoning pattern in clinopyroxene from the Kokchetav diamond-grade metamorphic rocks: Missing part of metamorphic history and location of second critical end point for calcsilicate system. Gondwana Res., 23, 920-930.

36. Mikhno A.O., Schmidt U., Korsakov A.V. (2013) Origin of K-cymrite and kokchetavite in the polyphase mineral inclusions from Kokchetav UHP calc-silicate rocks: evidence from confocal Raman imaging. Europ. J. Miner., 25, 807-816.

37. Musiyachenko K.A., Korsakov A.V., Letnikov F.A. (2021) A New Occurrence of Maruyamaite. Dokl. Earth Sci., 498, 403-408 (translated from Dokl. RAN., 498, 58-65).

38. Musiyachenko K.A., Korsakov A.V., Shimizu R., Zelenovskiy P.S., Shur V.Y. (2020). New insights on Raman spectrum of K-bearing tourmaline. J. Raman Spectroscopy, 51, 1415-1424.

39. Ogasawara Y., Fukasawa K., Maruyama S. (2002) Coesite exsolution from supersilicic titanite in UHP marble from the Kokchetav massif, northern Kazakhstan. Amer. Miner., 87 , 454-461.

40. Ota T., Kobayashi K., Kunihiro T., Nakamura E. (2008) Boron cycling by subducted lithosphere; insights from diamondiferous tourmaline from the Kokchetav ultrahigh-pressure metamorphic belt. Geochim. Cosmochim. Acta, 72, 3531-3541.

41. Perchuk L.L., Safonov O.G., Yapaskurt V.O., Barton J.M.B. (2002) Crystal-melt equilibria involving potassium-bea-ring clinopyroxene as indicator of mantle-derived ultra-high-potassic liquids: an analytical review. Lithos, 60, 89-111.

42. Perchuk L.L., Yapaskurt V.O. (1998) Mantle-derived ultra-potassic liquids. Geol. Geophys., 39(12), 1756-1765.

43. Romanenko A.V., Rashchenko S.V., Sokol A.G., Korsakov A.V., Seryotkin Y.V., Glazyrin K.V., Musiyachenko K. (2021) Crystal structures of K-cymrite and kokchetavite from single-crystal X-ray diffraction. Amer. Miner., 106, 404-409.

44. Rozen O.M., Zorin Yu.M., Zayachkovsky A.A. (1972) A find of diamond linked with eclogites of the Precambrian Kokchetav massif. Dokl. AN SSSR, 203, 674-676. (In Russ.)

45. Safonov O.G. (2007) Models for the evolution of deep alka-line fluids. Doct. geol. and min. sci. diss. Moscow, 403 с.

46. Safonov O.G., Perchuk L.L., Litvin Y.A., Bindi L. (2005) Phase relations in the CaMgSi2O6-KAlSi3O8 join at 6 and 3.5 GPa as a model for formation of some potassium-bearing deep-seated mineral assemblages. Contrib. Mineral. Petrol., 149, 316-337.

47. Schulze D.J., Helmstaedt H. (1988) Coesite-Sanidine Eclogites from Kimberlite: Products of Mantle Fractionation or Subduction? J. Geol., 96, 435-443.

48. Seki Y., Kennedy G.C. (1964) The breakdown of potassium feldspar, KAlSi3O8 at high temperatures and high pressures. Amer. Miner., 49, 1688-1706.

49. Shatsky V.S., Sobolev N.V., Vavilov M.A. (1995) Diamond-bearing metamorphic rocks of the Kokchetav massif (northern Kazakhstan). ultra-High Pressure Meta-morphism. Cambridge, Cambridge University Press, 427-455.

50. Shimizu R., Ogasawara Y. (2005) K-Tourmaline in diamond-bearing rock from Kokchetav. Mitteilungen der Osterreichischen Mineralogischen Gesellschaft, 150.

51. Shimizu R., Ogasawara Y. (2013) Diversity of potassium-bearing tourmalines in diamondiferous Kokchetav UHP metamorphic rocks: A geochemical recorder from peak to retrograde metamorphic stages. J. Asian Earth Sci., 63, 39-55.

52. Smith D.C. (1984) Coesite in clinopyroxene in the Caledonides and its implications for geodynamics. Nature, 310, 641-644.

53. Smyth J.R., Hatton C.J. (1977) A coesite-sanidine grospydite from the Roberts Victor kimberlite. Earth Planet. Sci. lett., 34, 284-290.

54. Sobolev N.V., Shatsky V.S. (1987) Carbon mineral inclusions in garnets of metamorphic rocks. Geolog. Geofiz., 28(7), 77-80. (In Russ.)

55. Sobolev N.V., Shatsky V.S. (1990) Diamond inclusions in garnets from metamorphic rocks: a new environment for diamond formation. Nature, 343, 742-746.

56. Sobolev N.V., Shatsky V.S., Vavilov M.A., Goryainov S.V. (1991) Coesite inclusion in zircon of diamondiferous gneisses of the Kokchetav massif: the first finding of coesite in metamorphic rocks on the territory of the USSR. Dokl. AN SSSR, 321, 184-188. (In Russ.)

57. Sobolev N.V., Shatsky V.S., Vavilov M.A., Goryainov S.V. (1994) Zircon of high-pressure metamorphic rocks from folded regions as a unique container of inclusions of diamond, coesite, and coexisting minerals. Dokl. RAN, 334, 488-492. (In Russ.)

58. Theunissen K., Dobretsov N.L., Korsakov A., Travin A., Shatsky V.S., Smirnova L., Boven A. (2000) Two contrasting petrotectonic domains in the Kokchetav mega-melange (north Kazakhstan): difference in exhumation mechanisms of ultrahigh-pressure crustal rocks, or a result of subsequent deformation? Island Arc, 9, 284-303.

59. Zedgenizov D.A., Kagi H., Shatsky V.S., Ragozin A.L. (2014) Local variations of carbon isotope composition in diamonds from Sao-Luis (Brazil): Evidence for heterogenous carbon reservoir in sublithospheric mantle. Chem. Geol., 363, 114-124.

60. Zhimulev F.I., Poltaranina M.A., Korsakov A.V., Buslov M.M., Druzyaka N.V., Travin A.V. (2010) Eclogites of the Late Cambrian-Early Ordovician North Kokchetav tectonic zone (northern Kazakhstan): structural position and petrology. Russ. Geol. Geophys., 51, 190-203 (translated from Geologiya i Geofizika, 51, 240-256).