The Manica greenstones belt in western Mozambique constitutes the eastern extension of the Odzi-Mutare greenstone belt in Zimbabwe that is one of several Archean greenstone belts within the Zimbabwe Craton. These greenstones are in Mozambique constituting the Manica Group and are subdivided in two main lithostratigraphic units: The Macequece Formation and the Vengo Formation. The former is hosting the Mundonguara Cu-Au mine and is dominated by volcanic rocks, while the younger Vengo Formation is consisting of epiclastic sedimentary rocks. This paper considers the character and origin of the ultramafic, mafic, and felsic rocks within the Macequece Formation. They include peridotitic komatiite, pyroxenitic komatiite, komatiitic cumulate rocks, gabbroic dykes, rhyolitic units, and a granitic rock intruding the komatiites. Samples of these rocks have been collected from outcrops and drill cores and are investigated through petrographic studies of thin sections and whole rock geochemistry including major and trace elements to interpret the geological environment and tectonic setting.The supracrustal rocks are metamorphosed to greenschist facies and the komatiites consists of varying proportions of serpentine, talc, chlorite, and amphibole. Primary features are partly preserved, with spinifex, vesicular, and cumulate textures. The komatiites are variously affected by carbonate alteration and deformation and the rhyolitic rocks are mostly strongly silicified. The komatiites are of the Al-undepleted type, with a MgO content of 25–45 wt %, while the mafic intrusions are tholeiitic in character, varying from gabbronorite to diorite in composition. Trace element diagrams used for interpretation of tectonic setting gives ambiguous results that could be an effect of crustal contamination of the ultramafic and mafic magmas. Using diagrams less sensitive to crustal contamination suggests the mafic and ultramafic magma to have a mantle source Minor rhyolitic rocks are chemically similar to granitic rocks intruding the komatiites and might have a mainly crustal magma source. This suggested that the Manica greenstones belt formed from magmas generated by mantle plume activity in a continental rift setting and were deposited on older Archean continental crust. These rocks are tentatively correlated with the Bends or Brookland formations belonging to the 2.9–2.8 Ga Mtshingwe Group in the Belingwe greenstone belts in Zimbabwe.

The Tangal-e-Sefid Fe–Cu mineralization forms syngenetic stratiform deposit in the Late Neoproterozoic volcano sedimentary sequence from the Central Iran. Early Cambrian metamorphic rocks are associated ore-bearing geologic units. The mineralization includes early oxide phase as a magnetite-rich bodies that are overprinted by a pyrite-chalcopyrite-rich sulfide phase. The most current alteration zone includes propylitic-carbonate, chlorite, sericite and silicic with a well-developed distribution of chloritization, especially in the layered part. Magnetite, pyrite and chalcopyrite comprise the primary main mineral assemblage, which is accompanied by malachite, covellite, hematite and goethite as the secondary minerals associated with epidote, chlorite, quartz and calcite minerals. Magnetite chemistry reveals the hydrothermal evolution of mineralization, and all the examined magnetite fall within fields of magnetite from VMS deposits. Fluid inclusion analysis of quartz and calcite coexisting with magnetite represent homogenization temperature range of 198 °C and 357 °C with a cooling trend from the massive toward the layered parts. The measured fluid salinity identifies two distinct medium-salinity fluids with mean values corresponding to 15 and 22 wt% NaCl. There is no significant difference in terms of temperature and salinity measured in calcite and quartz minerals. However, the average measured temperature values of fluids trapped in calcite (189–336 °C) are slightly lower than quartz (227–357 °C). Since the ore deposit distribution is spatially associated with actinolite schist, thermometric data of actinolite show temperature fluctuations of 310–315 °C and mineral formation pressures of 2.5–3 Kbar, which are correlated with the low-grade metamorphism.

Primary hydrothermal fluids derived from submarine magmatism in an extensional system of seafloor were enriched in Fe and Cu (± Zn and possibly Pb) and it is the responsible for the first stage of magnetite formation and following the overprinting pyrite and chalcopyrite mineralization. The ore deposit geometries associated with magnetite mineralization and sulfide replacement styles; reveals that in the second stage of mineralization, hydrothermal fluid is mixed with oceanic water and eventually metal sulfides are deposited. The mineralizaton zone associated with the volcano-sedimentary sequence is affected by low-grade regional metamorphism related to Pan-African orogeny and represent the green schist territory as the VMS deposits related to Archean.

The metamorphosed, stratiform, c. 1.9 Ga Zinkgruvan Zn-Pb-Ag deposit is one of Europe’s largest producers of Zn. Since 2010, disseminated Cu mineralization is also mined from dolomite marble in a hydrothermal vent-proximal position in the stratigraphic footwall. Local enrichments of Co and REE exist in the vent-proximal mineralization types, albeit their distribution is poorly known. This contribution provides new data on the distribution of Co and REE within the Zinkgruvan deposit.

LA-ICP-MS analysis suggest that lattice-bound cobalt in sphalerite range between 44 ppm and 1372 ppm, with the lowest and highest values occurring in distal and proximal mineralization, respectively. Proximal Co-rich sphalerite is always Fe-rich. Lattice-bound Co also occur in pyrrhotite; ranging from 52 ppm in distal ore to 1608 ppm in proximal ore. There is a concurrent increase in lattice-bound Ni from 3 ppm to 529 ppm. In proximal ore, Co is also hosted by cobalt minerals such as costibite (27.37 wt.% Co), safflorite (16.21 wt.% Co), nickeline (7.54 wt.% Co), cobaltite (32.74 wt.% Co) and cobaltpentlandite (25.49 wt.% Co). Automated quantitative mineralogy suggest that these minerals are highly subordinate to sphalerite (<70.11%) and pyrrhotite (<14.69%), amounting to <2.88% cobalt minerals with safflorite being most common (up to 2.67%). Cobalt deportment calculations suggest that the proportion of whole-rock Co that is lattice-bound to sphalerite and pyrrhotite ranges from 7.80% to 100%, with sphalerite being the main host. Whole-rock As and Ni contents pose a strong control on whether Co occurs lattice-bound or as Co minerals.

LA-ICP-MS analysis show that accessory apatite in proximal, marble-hosted Cu mineralization carries a few thousand ppm ∑REE, but locally up to c. 1.6 wt.% ∑REE. The apatite can be subdivided into two types. Type 1 apatite is characterized by dumbbell-shaped chondrite-normalized REE profiles with relative enrichment of in particular Sm-Tb, depletion of Yb-Lu relative to La-Pr, local positive Gd anomalies, and weak positive to negative Eu anomalies. Type 2 apatite is characterized by flat to negatively sloping REE profiles from La to Gd and relative HREE depletion. Additional REE is hosted by monazite. Type 1 apatite was only found as a gangue to Cu mineralization. The Type 1 apatite REE signature is characteristic of hydrothermal apatite, and a direct genetic association with vent-proximal Cu mineralization can be inferred.

Comparison with published REE contents in apatite suggest that vent-proximal Zinkgruvan apatite is locally as REE-rich as apatite from Kiruna-type apatite iron oxide deposits, and more REE-rich than apatite in other metamorphosed sediment-hosted sulphide deposits in the world, such as the Gamsberg deposit (RSA).

The Narm deposit is located in the Kuh-e-Sarhangi district which is a main part of the most significant Iranian iron mineralization belt, the Kashmar-Kerman Tectonic Zone (KKTZ) in Central Iran. The Narm deposit comprises an estimated total of ∼ 135000 tons of iron ore with an average grade of ∼ 55% Fe and is hosted in Early Cambrian volcano sedimentary rocks of the Rizu formation. Ore occurrences in this deposit consist of lens-shaped magnetite ore bodies, magnetite-apatite-actinolite veins and locally rare brecciated dolomite with magnetite clasts. Magnetite, pyrite, chalcopyrite and specularite associated with apatite, actinolite, biotite and carbonate minerals form the primary main mineral assemblage which is accompanied by hematite and goethite as the secondary minerals. Magnetite as the most current mineral of Narm deposit reveal the magmatic to hydrothermal evolution of mineralization. Magmatic magnetite minerals (Mag I) are dark-gray inclusion-rich magnetite spatially correlated with high temperature Ca-Fe alteration. The brighter inclusion-free hydrothermal magnetite groups (Mag II and Mag III) form during the temperature decreasing of the mineralizing fluid. According to the magnetite chemistry examination, most magnetite fall into the field for magnetite from iron-oxide apatite (IOA) deposits. Apatite minerals with F/Cl >2, belong geochemically to the fluorapatite type. In addition to the primary dolomite, there are some hydrothermal Fe-rich dolomites and Mn bearing ones, indicating the hydrothermal fluid playing the important role for Fe-rich mineralization. In respect to fluid evolution, fluid inclusion analysis of calcite and apatite minerals form the magnetite paragenesis assemblage represent homogenization temperature range for fluid between 325-557℃. The salinity of fluid varied from 7.7 to 11.6 wt % NaCl equivalent and a cooling trend with the dominant chlorine complex as an agent for deposition of the Fe-rich ores. The geochemical characteristics of the δ¹⁸O_fluid values of magnetite (from +6.1 to +10.4‰) and δ¹⁸O_fluid values of actinolite (from +7.7 to +12.5‰) represent the magmatic-hydrothermal (δ¹⁸O_fluid > + 0.9 ‰) formation process. The iron rich Al-clinochlore composition from the alteration zone indicates a temperature range between 250 and 330℃ which points to a temperature reduction of hydrothermal fluids in this mineralizing zone. The integrated geochemical data from this investigation, including mineral chemistry, microthermometry of fluid inclusions and oxygen isotope data all reveal a magmatic-hydrothermal genesis for this deposit.

Geodynamically, the Kashmar-Kerman Tectonic Zone (KKTZ) is one of the most perplexing tectonomagmatic belts of the Central Iran Microcontinent (CIM), comprising two important districts, Bafq and Kuh-e-Sarhangi. The Late Neoproterozoic-Early Cambrian granitoids, metamorphic rocks, and mildly metamorphosed volcansedimentary sequences are the oldest geologic outcrops in the Narm area, which is located in the western part of Kuh-e-Sarhangi. Alkaline gabbro-diorites with relatively high contents of K2O (1.99–3.03 wt%) and Na2O (2.7–5.99 wt%) are among the youngest intrusive rocks in the area, representing a within-plate provenience. These rocks were emplaced into Paleozoic sedimentary units as mafic-intermediate stocks, sills and dykes. Geochemically, these rocks could have resulted directly from partial melting (e.g., FeOT/MgO>1, Nb/La>0.5) with no considerable indication of assimilation with crustal materials (e.g., Ti/Zr > 30, Ti/Y > 200). Assimilation and fractional crystallization cannot account for magma evolution of gabbro-diorite rocks in the Narm area, using rare earth element ratios and geochemical models. There are also some geochemical signatures of an asthenospheric origin for the Narm gabbro-diorite rocks, such as the low ratios of La/Nb (1.5) and La/Ta (22). U–Pb zircon ages show that the Narm gabbro-diorites formed during two major episodes of magmatism in Central Iran: 40.3 ± 0.1 Ma in the Late Eocene (Bartonian) for gabbroic units and 8.04 ± 0.05 and 7.86 ± 0.05 in the late Miocene (Tartonian) for diorite stocks and diorite sills, respectively. Despite a time difference of more than thirty million years, geochemical similarities between the Eocene gabbro rocks and the Miocene diorite from the Narm area are striking. It is proposed that the best scenarios for the west of Kuh-e-Sarhangi mafic-intermediate magmatic pulses along with the deep faults of the Central Iran, are an Eocene magmatic flare up and a Miocene asthenosphere upwelling. Temporally and spatially, these rocks are comparable to the Cenozoic alkaline intrusive rocks of the Bafq region.