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The data were generated in two labotories of the Dalhousie University in Halifax during a series of experiments to determine the solubility of chromite in komatiite mixed with different crustal contaminants. The experiments were designed to determine the solubility of the mineral chromite in silicate melt, with the dominant variable being the silica and iron content of the melt. After equilibrating chromite with melt at 1192-1430 degrees Celcius, samples were quenched and the composition of the chromite, quenched melt (now glass), and olivine run-products were measured for major and minor elements by electron microprobe, and the chromium concentration in the glass was measured by laser ablation ICP-MS. Analytical procedures are included in the associated data description file. The data are provided in a series of Excel worksheets containing five data tables. Table 1 is a summary of the composition of the starting materials used in experiments. Table 2 is a summary of the conditions of temperature, oxygen fugacity, experiment duration and initial sample composition. Table 3 is a summary of the major and minor element composition of the glass measured by electron microprobe and laser ablation ICP-MS. Tables 4 and 5 are summaries of the major and minor element composition of the olivine and chromite, respectively, measured by electron microprobe.
This data set is the source of my doctoral thesis and of three resulting publications. Through whole rock geochemistry of selected samples and microprobe and geochronological analyses of key minerals, formerly selected by extensive microscopical studies, standard geothermobarometry and modelling was applied. It has been shown that metamorphic rocks, in particular, the eclogites of the northern Kaghan Valley, Pakistan, were buried to depths of 140-100 km (36-30 kbar) at 790-640°C. Subsequently, cooling during decompression (exhumation) towards 40-35 km (17-10 kbar) and 630-580°C has been superseded by a phase of reheating to about 720-650°C at roughly the same depth before final exhumation has taken place. In the southern-most part of the Kaghan Valley, amphibolite facies assemblages with formation conditions similar to the deduced reheating phase indicate a juxtaposition of both areas after the eclogite facies stage and thus a stacking of Indian Plate units. Radiometric dating of zircon, titanite and rutile by U-Pb and amphibole and micas by Ar-Ar reveal peak pressure conditions at 47-48 Ma. With a maximum exhumation rate of 14 cm/a these rocks reached the crust-mantle boundary at 40-35 km within 1 Ma. Subsequent exhumation (46-41 Ma, 40-35 km) decelerated to ca. 1 mm/a at the base of the continental crust but rose again to about 2 mm/a in the period of 41-31 Ma, equivalent to 35-20 km. Apatite fission track (AFT) and (U-Th)/He ages from eclogites, amphibolites, micaschists and gneisses yielded moderate Oligocene to Miocene cooling rates of about 10°C/Ma in the high altitude northern parts of the Kaghan Valley using the mineral-pair method. AFT ages are of 24.5±3.8 to 15.6±2.1 Ma whereas apatite (U-Th)/He analyses yielded ages between 21.0±0.6 and 5.3±0.2 Ma. The southern-most part of the Valley is dominated by younger late Miocene to Pliocene apatite fission track ages of 7.6±2.1 and 4.0±0.5 Ma that support earlier tectonically and petrologically findings of a juxtaposition and stack of Indian Plate units. As this nappe is tectonically lowermost, a later distinct exhumation and uplift driven by thrusting along the Main Boundary Thrust is inferred. Out of this geochemical, petrological, isotope-geochemical and low temperature thermochronology investigations it was concluded that the exhumation was buoyancy driven and caused an initial rapid exhumation: exhumation as fast as recent normal plate movements (ca. 10 cm/a). As the exhuming units reached the crust-mantle boundary the process slowed down due to changes in buoyancy. Most likely, this exhumation pause has initiated the reheating event that is petrologically evident (e.g. glaucophane rimmed by hornblende, ilmenite overgrowth of rutile). Late stage processes involved widespread thrusting and folding with accompanied regional greenschist facies metamorphism, whereby contemporaneous thrusting on the Batal Thrust (seen sometimes equivalent to the MCT) and back sliding of the Kohistan Arc along the inverse reactivated Main Mantle Thrust caused final exposure of these rocks. Similar circumstances have been seen at Tso Morari, Ladakh, India, 200 km further east where comparable rock assemblages occur. In conclusion, as exhumation was already done well before the initiation of the monsoonal system, climate dependent effects (erosion) appear negligible in comparison to far-field tectonic effects. Thus, the channel flow model is not applicable for this part of the Himalayas.
During the Egyptian 18th dynasty (c. 1550–1292 BC), cobalt ore was mined, processed and used as a colourant for glass, faience and blue-painted pottery. Co-coloured glass objects have a mid- to dark blue colour and were produced in order to imitate the semi-precious stone lapis lazuli. During this period, the glass objects were manufactured predominantly at two sites: Malqata (25°42'51.2"N 32°35'33.4"E) and Amarna (27°38'40.3"N 30°53'55.0"E).Major, minor and trace element concentration data from 38 blue glass objects from Amarna in the collection of Egyptian Museum and Papyrus Collection in Berlin are reported in this data publication. For comparison, glass objects from the same period and location, but of different colours (one red, two each of colourless, green and turquoise-blue glass) were analysed with the same method. These objects were originally brought to Berlin subsequent to the 1911–1914 excavations at Amarna carried out under the direction of Ludwig Borchardt on behalf of the Deutsche Orient-Gesellschaft. Unfortunately, most of these have by now lost their specific finds location. In addition, two recent samples of cobalt ore from the region of Ain Asil, near the Dakhla oasis (25°30'59.6"N 29°09'59.8"E), were included in the analysis.
The Morro São João intrusion is located in the easternmost part of the Serra do Mar province, along the Cabo Frio lineament (Fig. 1) and has an area of approximately 10 km². It is a Late Cretaceous intrusion formed by clinopyroxenites, melagabbros, shonkinites, malignites, nepheline syenites, and phonolite dikes, without olivine, and is thought to have formed by closed system crystallization of a fairly evolved tephritic melt of potassic/ultrapotassic affinity (cf. Brotzu et al., 2007). We have analyzed two malignites, and specifically, their liquidus phases (clinopyroxene, titanite, garnet, amphibole). Analyzing the trace elements in these minerals helps us to better understand the different fractionation of the elements in these coexisting phases, and the implications for the evolution processes that occurred in the Morro São João magma reservoir. These analyses also provided important information about the concentration of rare earth elements (REEs) and high field strength elements (HFSEs), and their change with the magmatic evolution of the suite. This publication results from work conducted under the transnational access/national open access action at Mass spectrometry la-icp laboratory (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
The Patagonia is a vast region located in the southernmost tip of the South America continent. It shows a basaltic plateau formed by volcanic activity started in the Upper Cretaceous-Lower Cenozoic (e.g., Baker et al. 1981; Ramos et al. 1982) and continued during Plio-Quaternary period. Long this time, the basalts have changed their compositions due to a variation in the tectonic environments. We studied mantle xenoliths hosted in the Plio-Quaternary alkaline basalts from Sierra Baguales, which are related to the back-arc environment (Munoz and Stern 1988, 1989; Munoz et al. 1989). Samples are recognized in two different areas (i) Cerro del Fraile and (ii) Cono Sin Nombre, which are situated to the NW and SE with respect to Sierra Baguales, respectively.
Zircon grains were separated from diorite and anorthosite dyke swarms intruding the mantle body of Finero Phlogopite Peridotite (Northernmost tip of the Ivrea-Verbano Zone, Southern Alps). All the dykes are highly discordant with respect to the mantle peridotite foliation and crop out along the right flank of the Rio Creves valley (Piedmont, Italy). The dykes are characterized by similar mineralogical composition, but show widely variable modal proportions.
Carbonate minerals are ubiquitous in most sediment-hosted mineral deposits. These deposits can contain a variety of carbonate types with complex paragenetic relationships. When normalized to chondritic values (CN), rare-earth elements and yttrium (REE+YCN) can be used to constrain fluid chemistry and fluid-rock interaction processes in both low- and high-temperature settings. Unlike other phases (e.g., pyrite), the application of in situ laser ablation-inductively coupled plasma-mass spectroscopy (LA-ICP-MS) data to the differentiation of pre-ore and hydrothermal carbonates remains relatively untested. To assess the potential applicability of carbonate in situ REE+Y data, we combined transmitted light and cathodoluminescence (CL) petrography with LA-ICP-MS analysis of carbonate mineral phases from (1) the Proterozoic George Fisher clastic dominated (CD-type) massive sulfide deposit and from (2) correlative, barren host rock lithologies (Urquhart Shale Formation). The REE+YCN composition of pre-ore calcite suggests it formed during diagenesis from diagenetic pore fluids derived from ferruginous, anoxic seawater. Hydrothermal and hydrothermally altered calcite and dolomite from George Fisher is generally more LREE depleted than the pre-ore calcite, whole-rock REE concentrations, and shale reference values. We suggest this is the result of hydrothermal alteration by saline Cl--rich mineralizing fluids. Furthermore, the presence of both positive and negative Eu/Eu* values in calcite and dolomite indicates that the mineralizing fluids were relatively hot (>250°C) and cooled below 200-250°C during ore formation. This study confirms the hypothesis that in situ REE+Y data can be used to differentiate between pre-ore and hydrothermal carbonate and provide important constraints on the conditions of ore formation.
The Upper Cretaceous Salitre intrusion, subdivided into Salitre I and Salitre II and dated to ~86-82 Ma by Sonoki and Garda (1988), is part of the Alto Paranaíba Igneous Province (APIP, Fig. 1) in Brazil, which is one of the largest ultrapotassic / carbonatitic / kimberlitic provinces in the world. The intrusion is characterized by the presence of lamproites, carbonatites and one lamprophyre (analyzed here), as well as along with a variety of intrusive cumulitic rocks. Among the Salitre studied samples, this alkaline lamprophyre is characterized by low SiO2 (35.6 wt%), ultrapotassic (K2O/Na2O = 5; K2O = 4.4 wt%) and peralkaline (PI = 1.3). It exhibits variable MgO content (14 wt%) and is enriched in REEs (∑REE=~1,300 ppm) and other trace elements (Nb, Ta, Zr, Hf, Sr, Ba). This lamprophyre is characterized by olivine and phlogopite phenocrysts set in a fine-grained groundmass of clinopyroxene, apatite, phlogopite, magnetite, chromite, and perovskite, with rare titanite and garnet; kalsilite is absent. Analyzing the trace elements of the main minerals in this lamprophyre helped us learn more about the origin and evolution of these magmas, as well as their possible genetic link with the other Salitre rocks. This analysis also provided important information about their enrichment in rare earth elements (REEs) and high field strength elements (HFSEs). This publication results from work conducted under the transnational access/national open access action at Mass spectrometry la-icp laboratory (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
The Salitre intrusion, which is subdivided into Salitre I and Salitre II. It was dated to ~86-82 Ma by Sonoki and Garda (1988). It is part of the Alto Paranaíba Igneous Province (APIP, Fig. 1) in Brazil. The APIP is one of the largest ultrapotassic/carbonatitic/kimberlitic provinces in the world. The intrusion consists of lamproites, carbonatites, and one lamprophyre, as well as various intrusive cumulitic rocks. These rocks include perovskite-phlogopite dunites, phlogopite-perovskite clinopyroxenites (salitrites, s.l.), phlogopitites, phoscorites, and perovskitites. These rocks are characterized by variable enrichment of olivine, clinopyroxene, phlogopite, perovskite, oxides, apatite, and carbonate, as well as several accessory phases, such as baddeleyite and calzirtite. Their geochemical and petrological features are related to the variable amounts of these minerals. For this part of the project, we have analyzed the concentrations of trace elements in the primary minerals (clinopyroxene, phlogopite, garnet, perovskite, apatite and olivine) identified in three phlogopite-perovskite clinopyroxenites and one perovskite-phlogopite dunite. Analyzing the trace elements in these minerals helped us to better understand the differential settling of minerals within the Salitre magma chamber, and their possible genetic relationship with carbonatitic and lamprophyric rocks. These analyses also provided important information about the minerals' enrichment in rare earth elements (REEs) and high field strength elements (HFSEs). This publication results from work conducted under the transnational access/national open access action at Mass spectrometry la-icp laboratory (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
The Limeira I kimberlite (91±6 Ma; Guarino et al., 2013) is part of the Alto Paranaíba Igneous Province (APIP) and was emplaced in the southern part of the São Francisco Craton in Brazil. This Kimberlite contains macrocrysts and phenocrysts of olivine, resorbed phlogopite/ tetraferriphlogopite, Al-free magnetite, chromite, magnesian ilmenite, rutile, perovskite, monticellite, apatite, serpentine and carbonate. It also contains a suite of xenocrysts and xenoliths (among which we recall wehrlite, phlogopite-ilmenite-websterite, olivine-ilmenite-glimmerite, clinopyroxenites bearing potassic-richterite, chromite-monticellite-kalsilite xenoliths, rutile with priderite or perovskite reaction rims, magnesian chromian ilmenite with perovskite rims). In this part of the project, we analyzed the xenocryst minerals and the main minerals found in the xenoliths entrapped in the Limeira I kimberlite. Analyzing the trace element concentrations in these minerals, helped us to better understand the processes that may occur in the subcontinental lithospheric mantle beneath the Alto Paranaíba Igneous Province. These analyses also provided important information about the minerals' enrichment in rare earth elements (REEs) and high field strength elements (HFSEs). This publication results from work conducted under the transnational access/national open access action at Mass spectrometry la-icp laboratory (IGG-CNR, Italy) supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
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