caa a22 4500 445390158 CHVBK 20180317143044.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s00710-010-0140-8 doi (NATIONALLICENCE)springer-10.1007/s00710-010-0140-8 Mineralogy, composition and PGM of chromitites from Pefki, Pindos ophiolite complex (NW Greece): evidence for progressively elevated fAs conditions in the upper mantle sequence [Elektronische Daten] [Argirios Kapsiotis, Tassos Grammatikopoulos, Basilios Tsikouras, Konstantin Hatzipanagiotou, Federica Zaccarini, Giorgio Garuti] The Pindos ophiolite complex, located in the northwestern part of continental Greece, hosts various chromite deposits of both metallurgical (high-Cr) and refractory (high-Al) type. The Pefki chromitites are banded and sub-concordant to the surrounding serpentinized dunites. The Cr# [Cr/(Cr + Al)] of magnesiochromite varies between 0.75 and 0.79. The total PGE grade ranges from 105.9 up to 300.0ppb. IPGE are higher than PPGE, typical of mantle hosted ophiolitic chromitites. The PGM assemblage in chromitites comprises anduoite, ruarsite, laurite, irarsite, sperrylite, hollingworthite, Os-Ru-Ir alloys including osmium and rutheniridosmine, Ru-bearing oxides, braggite, paolovite, platarsite, cooperite, vysotskite, and palladodymite. Iridarsenite and omeiite were also observed as exsolutions in other PGM. Rare electrum and native Ag are recovered in concentrates. This PGM assemblage is of great petrogenetic importance because it is significantly different from that commonly observed in podiform mantle-hosted and banded crustal-hosted ophiolitic chromitites. PGE chalcogenides of As and S are primary, and possibly crystallized directly from a progressively enriched in As boninitic melt before or during magnesiochromite precipitation. The presence of Ru-bearing oxides implies simultaneous desulfurization and dearsenication processes. Chemically zoned laurite and composite paolovite-electrum intergrowths are indicative of the relatively high mobility of certain PGE at low temperatures under locally oxidizing conditions. The PGM assemblage and chemistry, in conjunction with geological and petrologic data of the studied chromitites, indicate that it is characteristic of chromitites found within or close to the petrologic Moho. Furthermore, the strikingly different PGM assemblages between the high-Cr chromitites within the Pindos massif is suggestive of non-homogeneous group of ores. Springer-Verlag, 2010 Kapsiotis Argirios Department of Geology, Section of Earth Materials, Panepistimiopolis of Rion, University of Patras, 265 04, Patras, Greece aut Grammatikopoulos Tassos SGS Canada Inc., Advanced Mineralogy Network, 185 Concession Street, K0L 2H0, Lakefield, ON, Canada aut Tsikouras Basilios Department of Geology, Section of Earth Materials, Panepistimiopolis of Rion, University of Patras, 265 04, Patras, Greece aut Hatzipanagiotou Konstantin Department of Geology, Section of Earth Materials, Panepistimiopolis of Rion, University of Patras, 265 04, Patras, Greece aut Zaccarini Federica Department of Applied Earth Sciences and Geophysics, University of Leoben, Peter Tunner Str. 5, A-8700, Leoben, Austria aut Garuti Giorgio Department of Applied Earth Sciences and Geophysics, University of Leoben, Peter Tunner Str. 5, A-8700, Leoben, Austria aut Mineralogy and Petrology Springer Vienna 101/1-2(2011-01-01), 129-150 0930-0708 101:1-2<129 2011 101 710 https://doi.org/10.1007/s00710-010-0140-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00710-010-0140-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kapsiotis Argirios Department of Geology, Section of Earth Materials, Panepistimiopolis of Rion, University of Patras, 265 04, Patras, Greece aut NATIONALLICENCE 700 1- Grammatikopoulos Tassos SGS Canada Inc., Advanced Mineralogy Network, 185 Concession Street, K0L 2H0, Lakefield, ON, Canada aut NATIONALLICENCE 700 1- Tsikouras Basilios Department of Geology, Section of Earth Materials, Panepistimiopolis of Rion, University of Patras, 265 04, Patras, Greece aut NATIONALLICENCE 700 1- Hatzipanagiotou Konstantin Department of Geology, Section of Earth Materials, Panepistimiopolis of Rion, University of Patras, 265 04, Patras, Greece aut NATIONALLICENCE 700 1- Zaccarini Federica Department of Applied Earth Sciences and Geophysics, University of Leoben, Peter Tunner Str. 5, A-8700, Leoben, Austria aut NATIONALLICENCE 700 1- Garuti Giorgio Department of Applied Earth Sciences and Geophysics, University of Leoben, Peter Tunner Str. 5, A-8700, Leoben, Austria aut NATIONALLICENCE 773 0- Mineralogy and Petrology Springer Vienna 101/1-2(2011-01-01), 129-150 0930-0708 101:1-2<129 2011 101 710 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer