The present study focuses on the bulk geochemistry and the mineral chemistry of pyrite, chalcopyrite, magnetite, and titanite. Pyrite and chalcopyrite are the most abundant ore minerals at Vathi and are related to potassic, propylitic, and sericitic hydrothermal alterations (A-and D-veins), as well as to the late-stage epithermal overprint (E ...
WhatsApp: +86 18221755073The Yamansu iron deposit, hosted in submarine volcanic rocks, is located in the Aqishan–Yamansu Fe–Cu metallogenic belt of eastern Tianshan, Xinjiang. New pyrite Re–Os and pyroxene diorite intrusion ages and the …
WhatsApp: +86 18221755073Whereas dissolution of magnetite associated with the pyritization of organic-rich sediments has been documented by several workers (e.g., Canfield and Berner, 1987), instances of the reverse process (magnetite replacement of pyrite) during the latter stages of diagenesis have also been reported (Reynolds, 1990; Suk et al., 1990).
WhatsApp: +86 18221755073Here, we simulate the sulfidic diagenesis of nano-magnetite in hydrothermal systems by incubating synthetic nanoparticles in anoxic artificial seawater at different sulfide:Fe ratios (4:1 and 1:4), pH (∼7 and ∼10), temperatures (20–80 °C), and in the presence or absence of added S 0, an important oxidant in pyrite forming reactions under anoxic conditions (Benning …
WhatsApp: +86 18221755073We present the results of an experimental study into the sulfidation of magnetite to form pyrite/marcasite under hydrothermal conditions (90–300°C, vapor saturated pressures), a process ...
WhatsApp: +86 18221755073Previous studies suggest that Co enrichment is mainly controlled by temperature, oxygen and sulfur fugacity, pH, and chloride content, with temperature being a key factor (Migdisov et al., 2011, Wang et al., 2022b, Guo et al., 2023, Liang et al., 2023a). The pyrite in magnetite ores in the Baijian Fe-Co deposit has significantly high sulfur ...
WhatsApp: +86 18221755073Pyrite and magnetite are some of the most common accessory minerals in many ore deposits. They form over a large spectrum of geological and hydrothermal conditions and incorporate various trace elements into their structure (e.g., Carew, 2004; Reich et al., 2005; Rusk et al., 2009; Large et al., 2009; Dupuis and Beaudoin, 2011; Ciobanu et al., 2012).
WhatsApp: +86 18221755073SEM back-scattered electron images of chalcopyrite from different mineralization stages from the quartz monzonite (a-c) and the latite (d-f): (a) chalcopyrite (Cpy) is intergrown with pyrite (Py ...
WhatsApp: +86 18221755073Magnetite-(apatite) rocks are grouped in well-defined clusters that are mostly related to continental magmatic arcs and extensional environments (Table 1).The host rocks are dominantly igneous, calc-alkaline to alkaline, and ranging in composition from felsic to mafic, with a predominance of the former (Table 1).Early studies (Meyer 1988; Hitzman et al. 1992) …
WhatsApp: +86 18221755073Request PDF | Sulfidation of nano-magnetite to pyrite: Implications for interpreting paleoenvironmental proxies and biosignature records in hydrothermal sulfide deposits | Nano-magnetite is a ...
WhatsApp: +86 18221755073Mineralisation occurs as narrow shear-hosted massive magnetite-pyrite-chalcopyrite-sphalerite ± pyrrhotite forming elongated, flattened pipe-like bodies. ... Moltzen, J. et al. Magnetite trace element characteristics and their use as a proximity indicator to the Avoca Tank Cu-Au prospect, Girilambone copper province, New South Wales, Australia ...
WhatsApp: +86 18221755073The chemical compositions of magnetite and pyrite can be used to determine source of ore-forming materials (Dare et al., 2014, Mukherjee and Large, 2017, Ding et al., 2018, Wang et al., 2017, Chen et al., 2018), the nature and evolution of the ore-forming fluid (Chen et al., 2015, Hu et al., 2017), and the mobility of elements during late-stage ...
WhatsApp: +86 18221755073The pyrite stability field increases from 300 to 100°C at lower Eh conditions. The gouge appears to have formed under anoxic conditions based on microbial observations at 1,000 m depth in TCDP core Hole A [Wang et al., …
WhatsApp: +86 18221755073LIMESTONES are an important source of palaeomagnetic data, with magnetite the dominant carrier of the magnetization. Because the magnetite is present in low concentrations, however, it has been directly observed only rarely and in trace amounts in acid-treated separates. Such residues are composed primarily of spheres, the ultimate origin of which has been …
WhatsApp: +86 18221755073Download scientific diagram | (a, b) Disseminated pyrite and magnetite grains distributed along linear features in fractures and pores. (c, d) Framboidal clusters of pyrite and magnetite in source ...
WhatsApp: +86 18221755073An experimental study of the mechanism of the replacement of magnetite by pyrite up to 300 degrees C. Gujie Qian, Joel Brugger, William Skinner, Guorong Chen, ... Chen, G & Pring, A …
WhatsApp: +86 18221755073Ferric complexes of oxalate, salicylate and acetylacetonate resulted in pyrite dissolution and magnetite formation. The activity of strongly reducing ligands (e.g., catechol) or unsaturated Fe(III)-exchange capacity (particularly in experiments with bentonite or with solutions of uncomplexed ligands) can result in an effective reduction of ferric iron concentration and …
WhatsApp: +86 18221755073Here, we simulate the sulfidic diagenesis of nano-magnetite in hydrothermal systems by incubating synthetic nanoparticles in anoxic artificial seawater at different sulfide:Fe …
WhatsApp: +86 18221755073The Gondpipri layered mafic–ultramafic intrusion at the western margin of the Bastar Craton in Central Indiacomprises leucogabbro, gabbronorite, and websterite. The intrusion hosts both magmatic and hydrothermal Ni-platinum group element (PGE)mineralisation. In this study, we use in-situ measured trace element composition of pyrite and magnetite and zircon …
WhatsApp: +86 18221755073A 'new' type of arsenian pyrite was formed during experimental replacement of magnetite under hydrothermal conditions (T = 125 and 220 °C; Psat) and in the presence of S(-II) and various As-containing species. The amount of As in pyrite depended on the As-source, with sources containing cationic As (As(II), As(III) and As(V)) resulting in considerably higher …
WhatsApp: +86 18221755073It is known that pyrrhotite may form by prolonged heating pathways, such as reaction of magnetite and pyrite at low-temperature (<200°C) as a result of burial diagenesis and anchimetamorphism (Gillett, 2003). ... This leaves thermal breakdown of pyrite (Bhargava et al., 2009; Lambert et al., 1998) or discharge of hydrothermal fluids ...
WhatsApp: +86 18221755073Pyrite (aka "fool's gold" or "iron pyrite") is a metallic looking material with numerous applications. Its chemical formula is FeS 2, meaning that it is a compound made up of iron (Fe) and Sulphur (S).
WhatsApp: +86 18221755073In this study the solubility of the univariant assemblage pyrite + pyrrhotite + magnetite has been determined in vapor saturated hydrothermal solutions from 200 to 350°C for NaCl concentrations ranging from 0.0 to 5.0 molal. At any temperature, oxygen and sulfur fugacities were buffered by the chosen assemblage. ... P.B. Barton et al ...
WhatsApp: +86 18221755073Reduced iron sulfides are more electrically conductive than pyrite and magnetite (Telford et al., 1990), and are found at higher concentrations in the anoxic zones (Risgaard-Petersen et al., 2012). Possibly the electron flow across the sediments occurs mostly through the reduced iron sulfides, the electron transfer takes place at the pyrite ...
WhatsApp: +86 18221755073DOI: 10.1016/J.GCA.2010.06.035 Corpus ID: 129327515; An experimental study of the mechanism of the replacement of magnetite by pyrite up to 300 °C @article{Qian2010AnES, title={An experimental study of the mechanism of the replacement of magnetite by pyrite up to 300 °C}, author={Gujie Qian and Jo{"e}l Brugger and William Skinner and Guorong Chen and Allan …
WhatsApp: +86 18221755073Geochimica et Cosmochimica Acta, 2008. This report describes a new form of arsenian pyrite, called As 3+ -pyrite, in which As substitutes for Fe [(Fe,As)S 2 ], in contrast to the more common form of arsenian pyrite, As 1À -pyrite, in which As 1À substitutes for S [Fe(As,S) 2 ].
WhatsApp: +86 18221755073Detailed rock magnetic experiments were conducted on high-purity natural crystalline pyrite and its products of thermal treatments in both argon and air atmospheres. In …
WhatsApp: +86 18221755073Much work has been devoted to understanding the formation of pyrite and marcasite (orthorhombic FeS 2) in aqueous solutions under diagenetic and hydrothermal conditions.Most …
WhatsApp: +86 18221755073La magnétite est une espèce minérale composée d' oxyde de fer(II,III), ferrimagnétique, de formule Fe (II) O.Fe (III) 2 O 3 avec des trace de magnésium Mg, de zinc Zn, de manganèseMn, de nickel Ni, de chrome Cr, de titane Ti, de vanadium V et d' aluminium Al. Elle fait partie du groupe des spinelles et forme une série avec la magnésioferrite et la jacobsite. ...
WhatsApp: +86 18221755073The flat time-resolved signals of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imply that trace elements exist mainly in the form of isomorphism in magnetite and pyrite with the exception some incompatible trace elements (e.g., Ca, K and Na in magnetite and Pb, Bi and Ag in pyrite).
WhatsApp: +86 18221755073the presence of magnetite-forming microbes (Stolz et al., 1990) and to augment geochemical profiles of early diagenetic processes (Karlin, 1990). Whereas dissolution of magnetite associated with ... The replacement of pyrite by magnetite may be considered to occur, like many other diagenetically and metamorphically formed minerals, by a surface ...
WhatsApp: +86 18221755073The Vathi porphyry Cu-Au±Mo deposit is located in the Kilkis ore district, northern Greece. Hydrothermally altered and mineralized samples of latite and quartz monzonite are enriched with numerous rare and critical metals. The present study focuses on the bulk geochemistry and the mineral chemistry of pyrite, chalcopyrite, magnetite, and titanite. Pyrite …
WhatsApp: +86 18221755073Geochimica et Cosmochimica Acta, 2013. A 'new' type of arsenian pyrite was formed during experimental replacement of magnetite under hydrothermal conditions (T = 125 and 220°C; P sat ) and in the presence of S(-II) and various As-containing species.
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