 | | Journal (article/letter/editorial) | | from the deeper mantle section of the northern Oman ophiolite and its tectonic implications Received:...first time in a podiform chromitite of the northern Oman ophiolite. The chromitite contains £ 1.5 ppm of total...order of abundance: (1) sulphides (Os-rich laurite, laurite–erlishmanite solid solution and an unnamed...the mantle to the crust (Naldrett 1981; Garuti et al. 1997). PGE-abundance systematics give us information...the early stage of the planet’s history (Jagoutz et al. 1979; Arculus and Delano 1981; O’Neill 1991). PGEs |  | | Journal (article/letter/editorial) | | PLATINUM-GROUP MINERALS IN PODIFORM CHROMITITES OF THE OMAN OPHIOLITE AHMED HASSAN AHMED§ AND SHOJI ARAI Department...part of the mantle section of the northern part of the Oman ophiolite. In terms of stratigraphic level...following order of abundance: (1) sulfides [Os-rich laurite, erlichmanite and unnamed (Ir,Rh)(Ni,Cu,Fe)2S3]...abundance of PGE sulfides, i.e., Os-rich laurite, in the Oman chromitites is ascribed to the sulfide-undersaturated...fugacity was sufficiently high to produce the Os-rich laurite and, to a lesser extent, erlichmanite and Ru-poor |  | | Journal (article/letter/editorial) | | magma in the reservoir [11]. Recently, Latypov et al. [14] argued for the importance of a pressure reduction...precipitate the stratiform chromitite (see Schulte et al. [2] for more details about stratiform chromitite)...chromitites [19,20] (Figure 1). The Cr# (= Cr/(Cr + Al) atomic ratio) of chromite is not so different; 0...and limited range of the Fe3+ ratio (Fe3+ /(Cr + Al + Fe3+ ) atomic ratio; <0.1) for the podiform chromitites...(iridium-group PGM), especially laurite [25], and some of stratiform chromitites contain laurite-bearing chromite [24 |  | | Journal (article/letter/editorial) | | nodular, anti-nodular, and layered varieties. Laurite is commonly found as minute (<5 μm diameter) solitary...variations to some discordant chromitites from the Oman ophiolite, a typical podiform chromitite interpreted...Takashima chromitite xenoliths indicate that the Oman discordant podiform chromitites were formed in a...before ophiolite obduction. Keywords: chromitite xenoliths, discordant chromitites, laurite, Takashima...Takashima alkali basalt, Oman ophiolite. INTRODUCTION Ultramafic xenoliths provide us with direct information |  | Ahmed, Ahmed H., Hanghøj, Karen, Kelemen, Peter B., Hart, Stanley R., Arai, Shoji (2006) Osmium isotope systematics of the Proterozoic and Phanerozoic ophiolitic chromitites: In situ ion probe analysis of primary Os-rich PGM. Earth and Planetary Science Letters, 245 (3) 777-791 doi:10.1016/j.epsl.2006.03.021 | Journal (article/letter/editorial) | | the Proterozoic ophiolite, Eastern Desert, Egypt, and in the Phanerozoic Oman ophiolite. Because they have...The three chromitite types in the northern part of the Oman ophiolite are almost indistinguishable in terms...1459, in platinum-group minerals in Egyptian and Oman ophiolites can be attributed to the diversity of...between the Proterozoic ophiolite of Egypt and the Phanerozoic ophiolite in northern Oman. The Os-isotope compositions...of the mantle chromitites in the Proterozoic ophiolite of Egypt clearly suggest crustal contamination |  | | Journal (article/letter/editorial) | | formation of chromite-oversaturated magmas. Spandler et al. (2005) found a mixing trend for the bulk CE chemical...around the chromitite (e.g., Cassard et al., 1981; Lago et al., 1982) (Fig. 1). Following the hypothesis...Yurimoto, 1994; Zhou et 4 ACCEPTED MANUSCRIPT al., 1994) (Fig. 2). Since then, podiform chromitites...various types (e.g., Proenza et al., 1999; Uysal et al., 2005; Borisova et al., 2012; Ahmed and Habtoor, 2015)...ophiolites (e.g., Robinson et al., 2004; Yang et al., 2007, 2015; Yamamoto et al., MA 2009). The whole framework |  | | Journal (article/letter/editorial) | | concordant and discordant chromitites from Oman ophiolite are of low-pressure origin, containing primary...ネル は の岩石の生成環境の指示者として重要である(例えば， (Mg, Fe2＋ )(Cr, Al, Fe3＋ )2O4 と表記されるが，他に Ti, Mn, Zn なども含み，その化学組成は極めて多様なことか... 上部マントルの主要な構成要素であるかんらん岩にはク みクロムスピネルの Cr /( Cr＋ Al )原子比 0.5 前後)であ ロムスピネルが 2 体積程度以下含まれる。かんらん岩の ることが多い(Arai...場合がある する。ポディフォーム・クロミタイトについては， 1980 (Cassard et al. 1981)(Fig. 1)。前者を非調和性クロミタイ ト( concordant chromitite... et al., 1981)(Fig. ム・クロミタイトが形成される。ポディフォーム・クロミ 年代初頭にその岩脈状の形状(Cassard et al., 1981; Lago et al., 1982)が明らかにされ，1990 |  | | Journal (article/letter/editorial) | | mantle level (e.g., Arai and Yurimoto, 1994; Zhou et al., 1994; Arai, 1997). The podiform chromitites serve...g., Robinson et al., 2004; Yang et al., 2007, 2011; Yamamoto et al., 2009; Xu et al., 2009), and this...discussed in great detail (e.g., Robinson et al., 2004; Ruskov et al., 2010). The important point is that, as...show nodular textures (e.g., Zhou et al., 1996; Yamamoto et al., 2009), which characterize igneous low-P...chromitites, enveloped by dunite (e.g., Cassard et al., 1981), are commonly found within mantle peridotites |  | Arai, Shoji, Miura, Makoto, Tamura, Akihiro, Akizawa, Norikatsu, Ishikawa, Akira (2020) Hydrothermal Chromitites from the Oman Ophiolite: The Role of Water in Chromitite Genesis. Minerals, 10 (3) 217 doi:10.3390/min10030217 | Journal (article/letter/editorial) | | Article Hydrothermal Chromitites from the Oman Ophiolite: The Role of Water in Chromitite Genesis Shoji...hydrothermal fluids, in the mantle to the crust of the Oman ophiolite. Here, we present petrologic characteristics...magmatic podiform chromitite by dominance of the Ca-Al silicates in the matrix. The fluids responsible for...(especially Pt and Pd). The fluids obtain Ca and Al from the crustal rocks and Cr from the mantle rocks...Keywords: hydrothermal chromitites; Ca-Al silicates; seawater; Oman ophiolite; slab-derived fluids; platinum-group |  | Habtoor, Abdel Monem, Ahmed, Ahmed Hassan, Akizawa, Norikatsu, Harbi, Hesham, Arai, Shoji (2017) Chemical homogeneity of high-Cr chromitites as indicator for widespread invasion of boninitic melt in mantle peridotite of Bir Tuluha ophiolite, Northern Arabian Shield, Saudi Arabia. Ore Geology Reviews, 90. 243-259 doi:10.1016/j.oregeorev.2017.03.010 | Journal (article/letter/editorial) | | melt in mantle peridotite of Bir Tuluha ophiolite, Northern Arabian Shield, Saudi Arabia Abdel Monem...melt in mantle peridotite of Bir Tuluha ophiolite, Northern Arabian Shield, Saudi Arabia, Ore Geology...melt in mantle peridotite of Bir Tuluha ophiolite, Northern Arabian Shield, Saudi Arabia Abdel Monem...author: ahmh2jp@yahoo.com Abstract The Bir Tuluha ophiolite is one of the most famous chromitite-bearing occurrences...chromitite pods are of high-Cr variety; Cr-ratio (Cr/(Cr + Al) atomic ratio) show restricted range between 0.73 |  | Idrus, Arifudin, Zaccarini, Federica, Garuti, Giorgio, Wijaya, I, Swamidharma, Yoseph, Bauer, Christoph (2022) Origin of Podiform Chromitites in the Sebuku Island Ophiolite (South Kalimantan, Indonesia): Constraints from Chromite Composition and PGE Mineralogy. Minerals, 12 (8) 974 doi:10.3390/min12080974 | Journal (article/letter/editorial) | | of Podiform Chromitites in the Sebuku Island Ophiolite (South Kalimantan, Indonesia): Constraints from...of Podiform Chromitites in the Sebuku Island Ophiolite (South Kalimantan, Indonesia): Constraints from...podiform chromitites in the Jurassic–Cretaceous ophiolite of Sebuku Island (South Kalimantan, Indonesia)...composition (Cr/(Cr + Al) > 0.7) occurs in the deep mantle, the other, high-Al (Cr/(Cr + Al) < 0.6), is located...affinity to IAT and MORB, for the high-Cr and high-Al chromitites, respectively. However, both are believed |  | | Journal (article/letter/editorial) | | D classified into two main types: primary high-Al (spinel Cr# <0.67) and high-Cr (spinel Cr#> TE ...olivine with subordinate pyroxenes, millerite, and laurite, were trapped within the chromian spinel during...mineral inclusions, K-phlogopites, Neoproterozoic ophiolite, 1. Introduction CE P Eastern Desert of Egypt...and high-Al) in the mantle section (e.g., Zhou et al., 1998; Uysal et al., 2009; Miura et al., 2012; Akmaz...Akmaz et al., 2014; Moghadam et al., 2015). The high-Cr chromitites have been in equilibrium with boninitic |  | | Journal (article/letter/editorial) | | ore minerals are Cr-spinel with high Cr# (Cr/(Cr + Al) = 0.8–0.83), as well as serpentine and chlorite...chromitite ores; Cr-spinel; olivine; amphibole; PGM; ophiolite; ultramafic rock; Kempirsai min13020263 Academic...deposits are the largest known ones, contained in ophiolite-type complexes, and are the second-most abundant...reserves, following the Bushveld chromite deposits. Ophiolite deposits are often referred to as so-called podiform...secondary changes. The genesis of chromitites of the ophiolite association is still the subject of debate. Possible |  | González-Jiménez, José María, Griffin, William L., Proenza, Joaquín A., Gervilla, Fernando, O'Reilly, Suzanne Y., Akbulut, Mehmet, Pearson, Norman J., Arai, Shoji (2014) Chromitites in ophiolites: How, where, when, why? Part II. The crystallization of chromitites. Lithos, 189. 140-158 doi:10.1016/j.lithos.2013.09.008 | Journal (article/letter/editorial) | | shows no consistent spatial location within the ophiolite “stratigraphy”. The second type (Type IIA) is...occur usually in the upper-mantle part of the ophiolite pseudosection, or near the crust-mantle boundary...Melcher et al., 1999; Proenza et al., 1999; Ahmed and Arai, 2002; Gervilla et al., 2005; Uysal et al., 2005...2008; Pagé and Barnes, 2009; Zaccarini et al., 2011; Borisova et al., 2012; Kapsiotis, 2013). Unraveling the...In this study, as in Part I (González-Jiménez et al., this volume), we accept the SC RI definitions |  | | Book | | bin Said Al Shanfari Minister of Petroleum and Minerals The Speech of H.E. Said Bin Ahmed Al Shanfari...Symposium Your Royal Highness Sayed Fahad Bin Mahmoud al Said, Your Royal Highness Members of the Honourable...pleasure to welcome you in this scientific gathering in Oman which has been made possible through the directives...contribute to the advancement of earth sciences. We, in Oman look forward with keen interest to the outcome of... I wish to thank the Ministry of Defence, Royal Oman Police and the Ministry of Information for their |  | | Journal (article/letter/editorial) | | harzburgite–dunite–chromitite complexes from the Neoproterozoic ophiolite, south Eastern Desert, Egypt: A possible recycled...high-Cr varieties. The average Cr-ratio (=Cr/(Cr + Al) atomic ratio) of chromian spinel in the chromitites...fertile mantle character with Al-rich chromian spinels (Cr-ratio = Cr/(Cr + Al) atomic ratio < 0.6), and... 1984; Arai, 1997a; Dilek and Thy, 1998; Arai et al., 2011). On the other hand, the refractory mantle...arc environments (e.g. Zhou et al., 1998; Dare et al., 2009; Arai et al., 2011). In many cases, ophiolites |  | Pujol-Solà, Núria, Proenza, Joaquín, Garcia-Casco, Antonio, González-Jiménez, José, Andreazini, Aleu, Melgarejo, Joan, Gervilla, Fernando (2018) An Alternative Scenario on the Origin of Ultra-High Pressure (UHP) and Super-Reduced (SuR) Minerals in Ophiolitic Chromitites: A Case Study from the Mercedita Deposit (Eastern Cuba). Minerals, 8 (10). 433pp. doi:10.3390/min8100433 | Journal (article/letter/editorial) | | in peridotites and associated chromitites from ophiolite complexes, along with minerals that typically...Amphibolite Complex) related to the onset of ophiolite obduction [16,23–39] (Figure 1a,b). The synorogenic...plate (Figure 1b) [23,27,28,35,36]. The Cuban Ophiolite Belt represents oceanic lithosphere obducted onto...Ophiolites The Mayarí-Baracoa ophiolite belt, in the eastern part of the Cuban Ophiolite Belt, outcrops for The...The Mayarí‐Baracoa ophiolite belt, in the eastern part of the Cuban Ophiolite Belt, outcrops for more |  | Xiong, Qing, Henry, Hadrien, Griffin, William L., Zheng, Jian-Ping, Satsukawa, Takako, Pearson, Norman J., O’Reilly, Suzanne Y. (2017) High- and low-Cr chromitite and dunite in a Tibetan ophiolite: evolution from mature subduction system to incipient forearc in the Neo-Tethyan Ocean. Contributions to Mineralogy and Petrology, 172 (6) doi:10.1007/s00410-017-1364-y | Journal (article/letter/editorial) | | and low‑Cr chromitite and dunite in a Tibetan ophiolite: evolution from mature subduction system to incipient...Al3+)] chromitites and dunites from the Zedang ophiolite in the Yarlung Zangbo Suture (South Tibet) have...Roeder 2001; Kamenetsky et al. 2001; Rollinson 2008; Gonzalez-Jimenez et al. 2011, 2014; Arai and Miura...Melcher et al. 1997; Ahmed and Arai 2002; Rollinson 2008; Uysal et al. 2009; Gonzalez-Jimenez et al. 2011;...2011; Morishita et al. 2011; Rollinson and Adetunji 2013; Zhou et al. 2014; Arai and Miura 2016). Integration |  | | Journal (article/letter/editorial) | | MR12A-01. [2] Goreva et al. (2001) American Mineralogist, 86, 466-472. [3] Ma et al. (2002) American Mineralogist... 269-276. [4] Ma et al. (2007) Canadian Mineralogist, 45, 551-557. [5] Ma et al. (2001) Canadian Mineralogist...3 7 4 4 [1] Oliver et al. (1984) GCA 48, 1759-1767. [2] PiersonWickman et al. (2001) EPSL 194, 165-175...et al. (2010) GCA 74, 4893-4901. [4] Lupton and Evans (2004) GRL 31, L13101. [5] Brennwald et al. (2013)...palaeothermometer to natural dolostone samples from the Northern Marion Platform (NMP, offshore NE Australia) and |
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