Bumerang pipe Ary Mastakh field Upper Anabar region Yakutia – relatively fertile mantle in the transitional part between Anabar shield and Magan trerrane Sergei Kostrovitsky and Igor Ashchepkov (1) Institute of Geochemistry SD RAS, Irkutsk (2)Sobolev’sInstitute of Geology Geophysics and Mineralogy SD RAS, Novosibirsk Am ga Lena Vi lyui Ol en e k E n i s ry Ba ika l la ke Norilsk Ol en ek - 1 - 3 - 2 Laptev sea - 4 - 6 - 5 1. 4. 3. 2. 7. 35. 16. 17. 15. 23. 9. 6. Anabar shield 8. 5. 11. 24. 25. 27. 29. 31. 32. 30. 10. 12. 13. 14. 18. 19. 11. 20. 11. 22. Aldan shield 26. 28. 33. 34. Yakutsk Irkutsk Anab ar I II IIIa IV X IX VIII VII VI IV IIIb 120 145 105 160 175 90 75 6 0 8 0 Bumerang, Kharadakh Ary –Mastakh field The Bumerang kimberlite pipe is unusual for the Anabar shield because it contain great amount of the pyroxene both of Cr diopside and pyroxenite type (after eclogite) and commonly in Anabar region the mantle is ultra-depleted and even garnets occurs rarely in kimbelrites Ashchepkov et al (2010, 2014; 2015;). This is because the pipe is close to the Margin of Anabar shield in the transition permeable zones. The PTX diagram show presence of the rare pyrope garnets to 6 GPa of lherzolitic pipe and grate amount of the eclogitic garnets mainly of Fe of type. Both eclogitic and Cr diopside garnets occurs mainly in the middle part of the SCLM within the in the pyroxenite layer. The ilmenite give long fractionation trend. From the LAB to the GPa 2.5 which is typical of the Magan terrane (Mir, Internationalnaya pipes etc.). The pyroxenes mostly have straight-line REE patterns, which create the fan - as series .They most depleted, have some Ba, U peaks of subduction type but deep Pb minima evidencing about the fractionations. The garnets of subduction type reveals the U peaks and all have EU, Sr, minima and varying Ba The HFSE minima are common But Ta>>Nb and Zr>Hf/ All this features evidences about possibility of finding of diamond bearing kimbertites within the suture zone between Magan terrane and Anabar shoed in the west part of Yakutian kimberlite province. Grant RFFI 19-05-00788