12-05-2017 0183 32 The purpose of this project is to present additional evidence for a magmatic origin of magnetite-apatite or Volcanic ash from El Laco, Chile, composed of fine-grained magnetite gray , small amounts of apatite thin white layer at right , sublimated iron phosphate violet hue at center , and a horizon with orange lumps of an iron-phosphorus-sulfur mineral below the ,...

Magnetite Mineral Facts Chemical Formula Fe 3 O 4 Magnetic Oxide of iron, Iron, 724 per cent Colors B lack and streak is black as well Hardness 6 Density 52 Cleavage No cleavage, magnetite breaks with an uneven choncoidal fracture Crystallography Cubic...

This monograph on Magmatic Ore Deposits has resulted from a Symposium held at Stanford University on November 12 and 13, 1966 All except three of the papers that were presented are published in this volume as well as some of the discussion and the summation of the symposium...

20-10-2016 0183 32 Magnetite chemistry has proven critical for understanding the transition from magmatic to hydrothermal conditions in Kiruna-type iron oxide-apatite IOA deposits LA-ICP-MS analysis of trace elements in apatite have also been used to understand the genesis of nelsonites and other apatite-oxide-rich rocks in magmatic environments 99 , 100...

This compositional contrast indicates that chemical composition of magnetite is largely controlled by the compositions of magmatic fluids and host rocks of the ores that have reacted with the fluids Moreover, a combination of petrography and magnetite geochemistry indicates that the formation of those ore deposits in the Qimantag metallogenic belt involved a ,...

Figure 1 A, Schematic section of a magmatic sulfide deposit showing the vertical gradation downward from disseminated to massive oreB, Generalized map showing massive sulfide mineral concentrations in footwall embayments of the Sudbury Complex Canada sequences may be related to major lithologic features such as cyclic-unit boundaries, unconformities, ,...

Magmatic Ore Deposits - Sede Medellin Magmatic Ore Deposits Magmatic ore deposits are those which are formed during crystallization of a magma, , magnetite, and becomes unavailable to concentrate in the late stage fluids Fluid conditions required to form tin oxide cassiterite are relatively reducing...

17-03-2015 0183 32 Magmatic magnetite ore deposits Occasionally granite and ultrapotassic igneous rocks segregate magnetite crystals and form masses of magnetite suitable for economic concentration A few iron ore deposits, notably in Chile, are formed from volcanic flows containing significant accumulations of magnetite phenocrysts...

Magnetite is a nearly ubiquitous accessory mineral in a wide variety of igneous and metamorphic rocks and an important primary and secondary constituent of many magmatic-hydro-thermal ore deposits In intermediate to felsic igneous rocks genetically associated with porphyry-type ore deposits, magne-...

Low-Ti, magnetite-apatite ore deposits occur associated with volcanic rocks in two belts in northern Chile Figure 1 one of Cenozoic age in the High Andean Cordillera, and one of Cretaceous age....

18-05-2021 0183 32 Serpentinite-hosted massive magnetite ore bodies are reported for the first time in the Late Cretaceous Sabzevar ophiolitic belt, northeastern Iran They show irregular and discontinuous shapes with variable sizes ranging from 30 to 60 cm Chromian spinel grains are observed within both magnetite ores and host serpentinite Magmatic chromian spinels, ,...

Magnetite-apatite MtAp rocks form a well-defined group of ore deposits characterized by the presence of massive magnetite with variable amounts of F -apatite, diopside/actinolite, and scapolite this type of massive orebody has sharp non-replacive contacts with the host...

Magmatic Ore Deposits - Sede Medellin Titaniferous magnetite deposits are magmatic accumulations of magnetite and ilmenite They commonly contain 02 to 1 percent V 2 0 5, most of which is concentrated in the magnetite, and they , magnetite ore or a magnetite concentrate of the ore by either of ,...

Magnetite chemistry vary depending on the ore forming environments and trace elements commonly found in magnetite structure have been used to discriminate between magmatic and hydrothermal systems such as Kiruna type apatite iron ore, Iron...

Gold-rich, porphyry-type ore deposits are associated with both oxidized and reduced magmatic intrusions Sillitoe 2000 Thompson and Newberry 2000 Rowins 2000 Oxidized ore deposits commonly contain primary magnetite, and form at oxygen fugacities between the nickel-nickel oxide NNO and hematite-magnetite HM oxygen fugacity buffers at the ....

Associated with these magmatic ore deposits are economic and sub-economic concentrations of Cu, Au, U, and REE Magnetite-apatite ores and some associated Fe- Cu- Au, Ag ....

than 300 million tons of ore, with between 10- to 45-percent titanium dioxide TiO 2 , 32- to 45-percent iron oxide FeO , and less than 02-percent vanadium V The origin of these typically discordant ore deposits remains as enigmatic as the magmatic evolution of their host rocks The deposits clearly have a magmatic origin, hosted...

Magmatic Ni-Cu ore bodies at Nunavik Nickel, like most similar deposits, are mainly composed of pyrrhotite Fe 1-x S and varying amounts of chalcopyrite CuFeS 2 and pentlandite Fe,Ni 9 S 8 From a geophysical point of view, these minerals are indistinguishable, and their global signatures will mostly depend on their texture ie disseminated, net-textured, semi-massive, ,...

21 lavas and pyroclastic deposits, but a magmatic origin is rejected by some geologists who regard 22 the ores as products of hydrothermal replacement of volcanic rocks This study describes 23 spherules of magnetite in the ore at Laco Sur, ,...

Working hypotheses include a purely magmatic origin involving separation of an Fe-, P-rich, volatile-rich oxide melt from a Si-rich silicate melt, and precipitation of magnetite from an aqueous ore fluid, which is either of magmatic-hydrothermal or non-magmatic surface or ,...

Fluid inclusions in magnetite-apatite ore from a cooling magmatic system at El Laco, Chile By Fernando Henriquez and Anthony Fallick Oxygen isotope composition of magnetite in iron ores of the Kiruna type in Chile and Sweden By Fernando Henriquez and Anthony Fallick...