1. Garnets of polimict breccia from Noyabrskaya kimberlite pipe (Yakutia) [1] Pokhilenko et al. (1999) Proceedings of the 7th International Kimberlite Conference: Cape Town, Red Roof Design, p. 690–707. [2] Lawless et al. (1979) AGU, 145-155. [3] Zhang et al. (2001) Contr. Mineral. Petrol. 141, 367-379. [4] Zhang et al. (2003) EPSL 216, 329- 346. [5] Pokhilenko (2009) LITHOS 112, 934-941. [6] Pokhilenko et al. (2014) Abstract book of the 30th International Conference on “Ore Potential of Alkaline, Kimberlite and Carbonatite Magmatism”, 131-134. [7] Griffin et al. (1999) Contr. Mineral. Petrol. 134, 232-250. A polymict breccia is a complex rare type of deep mantle rocks. Such rocks were previously described just in some papers [2-5]. Each polymict breccia is unique. SH-18-20 is a conglomerate of peridotite fragments of different composition. The rock forming conditions were nonequilibrium. Conglomeration of fragments took place in the mantle before the introduction of the kimberlite melt. Composition of garnets varies without a definite correlation between the elements within a fragment of a sample and grain zones (wt.%): TiO 2 0-1.87; Al 2 O 3 19.08-22.58; Cr 2 O 3 0.31-5.55; FeO 5.85-11.41; MnO 0.-0.61; MgO 18.08- 21.59; CaO 4.95-6.59. The other minerals compositions were described in [6]. 5 cm Chondrite-normalised REE patterns in garnets show varying degrees and character of enrichment, indicating the different sources of metasomatism or/and several stages of the process. Light REE enrichment may be caused by the influence of prekimberlitic melt. Summary chart of chondrite-normalised REE patterns: 1,2 – center and rim of a garnet with lherzolitic CaO-Cr 2 O 3 relation; 3,4 – garnet near a crack; 5 – garnet inclusion in cpx; 6,7 – low Cr garnets. According to Zr-Ti and Zr-Y signatures (modified after [7]) the most of studied garnets were exposed to high-T metasomatism (Melt Metsomatism) [7]. “Central” part of a lherzolitic garnet (1) as well as a garnet inclusion in cpx (5) were depleted with these components. [1] ) Element distribution in garnets from the profiles A, B, C. B A C Core Rim C As in other polymict breccias we observed zoning in some garnet grains from our sample (for example, A, B, D). But it was not usual zoning “core-rim”-samples [2-5 ]; it was zoning with irregular spots in the most unexpected places. Very likely that effect of the fluid/melt was multiple and uneven Some garnets have kelyphitic rims similar to those for pyrope peridotite assemblages containing high-Al pyroxenes of variable composition, Al-spinel. Our data (red diamonds) were plotted on a chart from [5] Mg/(Mg+Fe)×100 vs. Ti/Cr plot for garnets from polymict breccia xenolith FRB1318, Premier Mine. Fields: 1 — garnets of of megacrysts suite; 2 — garnets from sheared lherzolites; 3 — garnets form metasomatized Cr-pyrope lherzolites; 4 — garnets from depleted high-Cr peridotites, including cpx-free harzburgites. dunite lherzolite Pxt & megacryst B C Chondrite-normalised REE patterns A D