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Milovanović Dragan., Eric Suzana., Seke Lajos. Milovanović Dragan., Eric Suzana., Seke Lajos. Petrology and metamorphism of amphibolites with corundum.

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Presentation on theme: "Milovanović Dragan., Eric Suzana., Seke Lajos. Milovanović Dragan., Eric Suzana., Seke Lajos. Petrology and metamorphism of amphibolites with corundum."— Presentation transcript:

1 Milovanović Dragan., Eric Suzana., Seke Lajos. Milovanović Dragan., Eric Suzana., Seke Lajos. Petrology and metamorphism of amphibolites with corundum from Prijepolje, Dinaridic ophiolite Belt (Southwestern Serbia) Petrology and metamorphism of amphibolites with corundum from Prijepolje, Dinaridic ophiolite Belt (Southwestern Serbia)

2 A L P S A P E N I N E S Geographic position of Serbia on Balkan Peninsula D I N A R I D E S T H K A R P A A B A L K E S O N I D

3 TISSIA Jadar block block Vardar zone Drina Ivanjica terran terran Belgrade The Mesozoic ophiolites in Serbia Dinaride ophiolite belt Amphibolites with corundum Vardar zone

4 The Mesozoic ophiolites in Serbia TISSIA Jadar block block Drina Ivanjica terran terran Belgrade Dinaride ophiolite belt Amphibolites with corundum Vardar zone Triassic limestone Ophiolitic melange Zlatibor peridotites Pillow lavas Triassic limestone Amphibolites with corundum Peridotites

5 The field trip observations Amphibilite with corundum Peridotites with Gr-Cpi veins Mafic granulites Amphibolite with corundum occur as lens, up to 100 m. thick tectonic contact with surroundig rocks, peridotites and mafic granulites 500 m Fault

6 The field trip observations Amphibolite with corundum occur as lens, up to 100 m. thick tectonic contact with surroundig rocks, peridotites and mafic granulites Mineral composition

7 Amphibole Piroxene Plagioclase Plagioclase with % An (average 95.18) Mineral composition

8 Corundum Corundum contain % Cr 2 O 3 Mineral composition Rock composition

9

10 Amphibole - plagioclase geothermometer (Blundy and Holland, 1990) Degrees of metamorphism 8-12 kB, C Al content in Ho ( Hammerstorm and Zen, 1986) 6-12 kB 1000 T ( 0 C) P (kbar) Qtz-absent Qtz-present W&N 91 S&D 94 Hbl Pl Qtz Grt Cpx L Grt Cpx Qtz Pl Opx Hbl Qtz L V Pl Opx Qtz Cpx Hbl L Hbl+Qtz= Opx+Cpx+Pl+V P&B 95 R 93 C 88 E&T 86 W&W 94 N&C 00 b N&C 00 a P 68, J 78 and WW 93 P&B 95 B&L 91 CWT 67 B 69 S 81 R 91 Experimental constraints

11 The maximum P-T condition still remains open. The most common mineral assemblage in the upper amphibolite facies for metabasites is Hbl+Pl±Qtz, with or without either Cpx or garnet. The genesis of Corundum: As a residue after partial melting as one of the liquides phases, with clinopyroxene and spinel or clinopyroxene and garnet for gabbroic anorthosite (Raheim&Green, 1974) Metamorphic origin by reaction spinel+anorthite = corundum+diopside in rocks with sufficiently high Al2O3 content, e.g. a troctolitic protholith This reaction needs spinel as one of the reactants, which may be formed by the raction olivine + plagioclase = orthopyroxene + clinopyroxene + spinel. (Kushiro&Yoder,1966) Replacement of Hbl+Pl±Qtz by combinations of Cpx, Pl + corundum is the main task of this study. Degrees of metamorphism

12 Whole-rock and mineral chemical compositions of AmC have cumulus origin, with a primary (?) mineral assemblage controlled by crystalization of olivine, plagioclase and clinopyroxene, as residue from primitive mantle (MORB source mantle ?). Protolith High Cr content ( ppm) imply formation from not evolved liquids. Eu and Sr positive anomalies reflect plagioclase accumulation, protolith have a cumulus origin (olivine gabbro ?) Subduction ?

13 High Cr content ( ppm) imply formation from not evolved liquids. Eu and Sr positive anomalies reflect plagioclase accumulation, protolith have a cumulus origin (olivine gabbro ?) Protolith Whole-rock and mineral chemical compositions of AmC have cumulus origin, with a primary (?) mineral assemblage controlled by crystalization of olivine, plagioclase and clinopyroxene, as residue from primitive mantle (MORB source mantle ?).

14 The absence of thermal relaxation features in Amc require rapid exhumation. Conclusions: After cooling at shallow levels olivin gabbro cumulates, together with surrounding peridotites undergone subduction and metamorphose under amphibole-granulite-eclogite facies, most probably related with Jurassic subduction during formation of Dinaridic ophiolite belt. During uplift and tectonical emplacement (closing of ocean space) the AmC was dismembered, forming fragments which were included in the ophiolite melange. Whole rock compositions, with positive Eu and Sr anomalies indicate that protoliths of Amc have a basic composition, olivine gabbro cumulates (?) Amphibilite with corundum Peridotites with Gr-Cpi veins Mafic granulites

15 Degrees of metamorphism of AmC and relation with ultramafic rocks is one of the important questions in genesis and emplacement of Dinaridic ophiolite belt. Conclusions: Ophiolites in Serbia and surrounding countries


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