Other language confidence: 0.9656043775919638
Black opal is a rare variety of opal-CT, which is pigmented by organic matter (OM) and can therefore be considered as an example of geo-bio interaction (Gouzy et al., 2025). The locality of Volyn, Ukraine with its famous chamber pegmatites is well-known for interaction between OM and igneous rocks (Franz et al., 2017). The locality was recently renamed Khoroshiv, but because in the geological-mineralogical literature the name Volyn was introduced, we use this name here. The intrusion of the pegmatites is closely connected to the intrusion of the host rocks, granites of the southwestern part of the Korosten Pluton, and the intrusion age was determined as 1.76 Ga (Shumlyanskyy et al., 2021). OM was identified as kerite (fossilized remains of organisms; Franz et al., 2023, and references therein), and in fluid inclusions in beryl and topaz (Vozniak et al., 2012; Vozniak and Pavlyshin, 2008). Furthermore, formation of NH4-bearing feldspar (buddingtonite) and muscovite (tobelite) in breccia (identified together with the pegmatites) point to the interaction between decayed OM and the igneous minerals (Franz et al., 2017). The timing of the interaction between OM and igneous (and other) fluids is an important question (Franz et al., 2024), and therefore we also give age constraints on the formation of the black opal, which from textural arguments seems to be one of the latest mineral formations. We give detailed information about the sample sites, the macroscopic features of the samples of different types of opal, and the analytical procedures. The description of the black opal samples is presented in images from secondary electron microscopy (SEM), back-scattered electron images (BSE) obtained with by electron microprobe (EMPA), element distribution maps obtained by µXRF (X-ray fluorescence), Fourier-transformed infrared spectroscopy (IR), and X-ray powder (XRD) characterization. Chemical analyses were obtained by wave-length dispersive (WDS) analyses with the EMPA as well as by energy-dispersive (EDX) analyses with both the SEM and the EMPA instruments, to identify and characterize inclusions in the black opal. Trioctahedral Li-mica (polylithionite) is included by opal in one sample, and because this type of mica has not been described in detail from the Volyn peg-matites, we present the EMPA analytical data here in detail. The presence of OM, which is known to absorb U in sufficient amounts, allows dating by the U-Pb decay system. The results of the isotopic dating with the laser-ablation sector-field inductively-coupled mass spectroscopy system (LA-SF-ICP-MS) is presented for the selected individual do-mains in three samples. The operating conditions are summarized in a separated pdf document.
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.
New major and trace element data on samples collected during the IODP (International Ocean Discovery Program) Expedition 396, ODP (Ocean Drilling Program) Leg 104, and DSDP (Deep Sea Drilling Project) Leg 38 on the Vøring margin, including 209 whole rocks analyses on hard rock samples (basalt, granite, andesite, dacite and rhyolite), 13 whole rock data on ash layers, and 381 in situ pXRF analyses on basaltic rocks.
These data represent the most complete set of analyses of the Eastern Australian Potassic suite. The data include whole-rock major-, trace-, and volatile-element analyses including loss-on-ignition measurements for 48 samples from 21 spatially distinct leucite-bearing volcanic surface expressions. These expressions range from topographically prominent volcanic edifices and mounds, through to lava flows, with four sample locations (8 samples total) coming from active quarry sites. Location and elevation data as well as methods used are provided. Trace-element data are available for 45 samples and include a total of 41 elements, while volatile-element data are available for 47 samples. All samples have major element analyses (10 elements). This is an update on the dataset provided in version 1 (https://doi.org/10.25625/AB5PLG). Additional information on the sample texture, description, and analytical methods has been added. This update also rectifies mismatches between some trace-element analyses and the corresponding samples. Data for Sn have been removed due to poor accuracy and precision.
The Valles Caldera, New Mexico, USA was created by two caldera-forming eruptions at ~1.6 and ~1.1 Myr. Since then, post-caldera activity has consisted of lava domes, lava flows, large explosive phases, and a hydrothermal system active today. Possibly the youngest eruption sequence, El Cajete, was emplaced 74.4 ± 1.3 ka (Zimmerer et al., 2016) and began with pyroclastic surges, followed by pyroclastic density currents (PDCs) and pumice-rich Plinian pyroclastic fall (Self et al., 1988). The objective of this project was to characterize crystal grains from the early El Cajete sequence, in terms of morphology and textures, using scanning electron microscopy (SEM). The early El Cajete differs from the later part of the sequence in its greater stratigraphic and lithologic complexity, having been formed from not only pyroclastic fall (like the later El Cajete) but also surge beds and PDCs. This dataset was collected under the national open access action at Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Pisa SEM/EDS facility supported by WP3 ILGE – MEET project, PNRR – EU Next Generation Europe program, MUR grant number D53C22001400005. This allowed me to obtain the present dataset of 31 cathodoluminescence (CL) images of 30 quartz crystals and one sanidine crystal.
We present comprehensive geochemical compositions and rheological properties of mantle peridotites from the Zhongba ophiolite. The geochemical dataset includes major element compositions of whole rock, as well as major and trace elements of olivine, orthopyroxene, clinopyroxene, and spinel. Water contents of olivine and pyroxenes are also provided. In addition, electron backscattered diffraction (EBSD) data includes calculated stress and detailed profiles. Analytical methods and supplementary figures are included to clearly present the dataset.
This dataset includes new geochemical and isotopic analyses for 10 samples from the Vitória dike swarm in southeastern Brazil. Analytical work was conducted at the Geoanalítica Core Facility of the Instituto de Geociências, University of São Paulo, and at the Geochronology Laboratory of the University of Brasília, both in Brazil.
The dataset includes a geological map and a table of whole rock analyses of pyroclastic deposits, intrusive bodies, and lava flows from Martin Vaz Archipelago, located in the Vitória-Trindade Ridge, South Atlantic. The data were collected during two field campaigns conducted in the Martin Vaz Island. The first campaign took place in 2011, while the second was carried out more recently, in 2022.
The melting relations, phase compositions, and trace element partitioning behavior during metasediment partial melting were investigated by high pressure and temperature experiments (300 and 900 MPa, 750–950 °C). The here published dataset includes all geochemical analysis of experimental products and starting materials, Raman identification of experimental minerals, and quantification of experimental phase proportions. From this dataset, we provided new insights into the origin of rare-metal enriched granites.
| Organisation | Count |
|---|---|
| Wissenschaft | 59 |
| Type | Count |
|---|---|
| unbekannt | 59 |
| License | Count |
|---|---|
| Offen | 59 |
| Language | Count |
|---|---|
| Englisch | 59 |
| Resource type | Count |
|---|---|
| Keine | 59 |
| Topic | Count |
|---|---|
| Boden | 36 |
| Lebewesen und Lebensräume | 36 |
| Luft | 7 |
| Mensch und Umwelt | 54 |
| Wasser | 10 |
| Weitere | 59 |