The K/T boundary layer in the Gams stratigraphic sequence, Eastern Alps, was determined to contain two spinel populations. One of them is dominated by Cr spinel, which originated from eroded high-pressure metamorphic rocks of eclogite composition, which are widespread in the Eastern Alps. This spinel is not only typical of the whole K/T boundary layer but was also found farther upsection in Maestrichtian clay. The other spinel population principally differs from the first one in having high Ni concentrations. Ni spinel from the Gams section differs by the high content of zinc up to 5.6% in a rust crust, that is not characteristic for other known sections at the K/T boundary. Alongside with well expressed crystals octahedral forms, one grain of drop-like mode of Ni spinel has been found. It is considered, that Ni spinel is confined to 1-3nbsp;mm rust colored layer which has deposited in less than 100 years, while in the Gams section it meets in all parts of the transition layer. The question of origin Ni spinel from the transitional layer at the K/T boundary remains opened and demands the further researches.
K/T boundary, spinel, impact, Eastern Alps.
1. Alvarez, Science, v. 208, 1980., doi:https://doi.org/10.1126/science.208.4448.1095
2. Barnes, J. Petrol., v. 42, 2001., doi:https://doi.org/10.1093/petrology/42.12.2279
3. Ben Abdelkader, Geobios., v. 21, 1997., doi:https://doi.org/10.1016/S0016-69959780098-8
4. Bohor, Earth Planet. Sci. Lett., v. 81, 1986., doi:https://doi.org/10.1016/0012-821X8690100-7
5. Byerly, Geochim. Cosmochim. Acta., v. 58, 1994., doi:https://doi.org/10.1016/0016-70379490099-X
6. Dolenec, Terra Nova., v. 12, 2000., doi:https://doi.org/10.1046/j.1365-3121.2000.00292.x
7. Ellwood, Earth Planet. Sci. Lett., v. 206, 2003., doi:https://doi.org/10.1016/S0012-821X0201124-X
8. Grachev, Izv. Phys. Solid Earth, v. 43, no. 9, 2007.
9. Grachev, Physicochemical and Petrophysical Studies in Earth Sciences, 7th Int. Conf., 2006.
10. Grachev, Russian J. Earth Sci., v. 7, no. 6, 2005., doi:https://doi.org/10.2205/2005ES000189
11. Graup, Earth Planet. Sci. Lett., v. 95, 1989., doi:https://doi.org/10.1016/0012-821X8990102-7
12. Janak, J. Metamorphic. Geol., v. 24, 2006., doi:https://doi.org/10.1111/j.1525-1314.2005.00619.x
13. Kamensky, Can. J. Earth Sci., v. 39, 2002., doi:https://doi.org/10.1139/e02-089
14. Keller, Int. J. Earth Sci., v. 88, 2000., doi:https://doi.org/10.1007/s005310050310
15. Kyte, Geochim. Cosmochim. Acta, v. 59, 1995., doi:https://doi.org/10.1016/0016-70379500343-6
16. Lenaz, Contrib. Mineral. Petrol., v. 139, 2000., doi:https://doi.org/10.1007/s004100000170
17. Melcher, J. Petrol., v. 45, 2004., doi:https://doi.org/10.1093/petrology/egh030
18. Melluso, J. Petrol., v. 36, 1995.
19. Mitchel, Am. Mineral., v. 63, 1978.
20. Montanari, Geology, v. 11, 1983., doi:https://doi.org/10.1130/0091-7613198311lt;668:SATCBAgt;2.0.CO;2
21. Mposkos, Earth Planet. Sci. Lett., v. 192, 2001., doi:https://doi.org/10.1016/S0012-821X0100478-2
22. Pober, Geol. Rundsch., v. 77, 1988., doi:https://doi.org/10.1007/BF01830175
23. Robin, Earth Planet. Sci. Lett., v. 107, 1991.
24. Robin, Earth Planet. Sci. Lett., v. 108, 1992., doi:https://doi.org/10.1016/0012-821X9290021-M
25. Robin, Geochim. Cosmochim. Acta., v. 60, 1996., doi:https://doi.org/10.1016/0016-70379500433-5
26. Rychagov, Transactions Doklady of the Russian Academy of Sciences, v. 356, 1997.
27. Sassi, Lithos., v. 78, 2004., doi:https://doi.org/10.1016/j.lithos.2004.05.002
28. Schulze, J. Geol., v. 104, 1996.
29. Shcheka, Platinum-Group mineralogy of PGE-Au placers of the Southern Far East, 2005.
30. Simandi, Science Sections., v. 356, 2005.
31. Smit, Nature, v. 310, 1984., doi:https://doi.org/10.1038/310403a0
32. Sobolev, Deep Nodules in Kimberlites and the Problem of the Upper Mantle Composition, 1974.
33. Sobolev, Nature, v. 343, 1990.
34. Sobolev, Lithos, v. 77, 2004., doi:https://doi.org/10.1016/j.lithos.2004.04.001
35. Stevens, Am. Mineral., v. 29, 1944.
36. Toppani, Geochim. Cosmochim. Acta., v. 67, 2003., doi:https://doi.org/10.1016/S0016-70370300383-1
37. Wagreich, Cretaceous Res., v. 26, 2005., doi:https://doi.org/10.1016/j.cretres.2004.11.012
38. Xu, Science, v. 256, 1992., doi:https://doi.org/10.1126/science.256.5053.80
39. Zakrzewski, Am. Mineral., v. 74, 1989.
40. Zhu, Earth Planet. Sci. Lett., v. 233, 2005., doi:https://doi.org/10.1016/j.epsl.2005.02.001
41. Zhu, J. Geol., v. 112, 2004.
42. Zolotukhin, Diversity of flood basalts and their parental magmas: An example of the Siberian Platform, 1989.
