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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.
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.
In this work we aimed to investigate and quantify the relative importance of dynamic conditions (e.g., stirring in a Concentric Cylinder apparatus) on the crystallization kinetics of basaltic magmas (Stromboli). This was achieved by observing the final textures of the samples, analysing the resulting SEM images, and finally relating the resulting parameters to specific growth and nucleation rates. The dataset is made of: 1) A folder called "SEM Images" with two sub-folders inside, representative of the two experiments carried out, called "CG1" and "CG2.3" 2) An Excel file, consisting in 4 data sheets, where all results of image analysis are included, divided in sections. The sheets are also available in CSV format. This publication results from work conducted under the transnational access/national open access action at High Pressure - High Temperature Laboratory (HPHT Lab), Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
OIB localities (e.g., Tristan, Samoa) have been considered ideal natural laboratories for studying mantle heterogeneity. Indeed, Sr, Nd, and Pb isotopes of lavas collected from OIB systems have provided insights into the existence of distinct mantle reservoirs, the origins of which are closely related to local tectonic processes: DMM, HIMU, EM1, and EM2. In this context, we aim to investigate the isotopic composition of noble gases in fluid inclusions trapped in xenoliths and lavas from Samoa and Tristan islands, two well-known enriched mantle (EM) localities. Our goal is to evaluate the role of noble gas cycling and active tectonic processes on the composition of the upper mantle. Our results show that CO2 is the most abundant volatile in all samples (lavas and xenoliths) from both localities. The 4He/20Ne ratio in most samples is lower than 150, suggesting the presence of atmospheric components in the fluid inclusions. This is further confirmed by the relatively low 40Ar/36Ar ratios, particularly in Tristan samples, which show values below 360. It is worth noting that the Samoa sample exhibits a 40Ar/36Ar ratio of 1000.4, the highest of the dataset. The Rc/Ra values (3He/4He corrected for atmospheric contamination) observed in the Samoa samples align with the Ar ratios mentioned above, as the 3He/4He ratio is the highest reported (13.32Ra). This is above the MORB range, indicating a contribution from lower mantle fluids, likely derived from the Samoan hotspot. In contrast, Tristan samples exhibit low Rc/Ra values, with an average of 5.12Ra. These low helium ratios suggest the presence of a more radiogenic, 4He-rich mantle. The low helium ratios may be related to the EM nature of the mantle. Previous studies in the Canary Islands have shown a decrease in 3He/4He ratios in the eastern part of the archipelago, where EM components have been identified (Hoernle et al., 1993; Simonsen et al., 2001; Day and Hilton, 2011, 2021; Sandoval-Velasquez et al., 2021). However, it is confirmed that an EM component can show a wide range of variation for the 3He/4He ratio, ranging from low values of 5-6Ra to values beyond the typical MORB range, which overlaps (and complicates the distinction) with other OIB contexts with HIMU signature. This publication results from work conducted under the transnational access/national open access action at INGV-Palermo- Noble gas laboratory supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005.
The study of textural and chemical characteristics of mafic minerals from mantle xenoliths is essential to investigate the nature of the upper mantle in a continental geodynamic context, melts generation and their effects related to mantle metasomatism. Particular textures in mantle minerals, inclusions or secondary veins of different nature (silicates vs carbonates), bubbles, represent petrographic tools to investigate these processes within the mantle. Petrographic 2D thin sections might overlook these mineralogical features, and 3D textural analysis through X-ray computed microtomography (micro-CT) are crucial to overcome these limitations. We focused on the Mt. Vulture volcano (southern Italy) rare mantle xenoliths, brought to the surface by a melilitite-carbonatite magma (141 ka), with particular emphasis to spinel-wehrlite xenoliths and wehrlitization processes that is located close to an area of intense CO2 degassing associated to catastrophic earthquakes. Preliminary results showed interesting 3D textural distributions within the studied xenoliths-forming mantle minerals. In particular, the micro-CT allowed to furnish new constrains on the relationship between fluids entrapment and migration, and structural discontinuities. Indeed, some minerals (especially those from the wehrlite xenoliths) showed a well-correlated distribution of fluid inclusions along the secondary fracturing planes. This publication results from work conducted under the transnational access/national open access action at Istituto Nazionale di Geofisica e Vulcanologia – Osservatorio Vesuviano (INGV-OV) and supported by WP3 ILGE - MEET project, PNRR - EU Next Generation Europe program, MUR grant number D53C22001400005. The author thanks also Gianmarco Buono and Lucia Pappalardo for their support during the analyses and the post processing process.
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 dataset contains full 40Ar/39Ar geochronological data completed by multi-collector noble-gas mass spectrometry using the laser total fusion technique on sanidine separated from the Drachenfels trachyte (Drachenfels, Bad Godesberg, Germany). The Drachenfels sanidine represents a useful intra-laboratory reference material for laser work. The purpose of the dataset is to share updated intercalibration data for the intra-laboratory Drachenfels sanidine, relative to the widespread fluence monitors Alder Creek sanidine and Fish Canyon sanidine, that can be used in future 40Ar/39Ar geochronological studies. W. McIntosh (New Mexico Geochronology Research Laboratory, Socorro, NM), P. Renne (Berkeley Geochronology Center, Berkeley, CA) and J.R. Wijbrans (Vrije Universiteit Amsterdam, NL) kindly provided splits of FCs, ACs and DRA1, respectively. The Ar laserprobe facility was realized with the financial support of CNR. The CO2 laser system was acquired within the PNRR – Mission 4, “Education and Research” - Component 2, “From research to business” - Investment line 3.1, “Fund for the creation of an integrated system of research and innovation infrastructures” - Project IR0000025 MEET.
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.
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