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Cathodoluminescence zoning images of Lower El Cajete quartz and sanidine crystals, Valles Caldera, New Mexico, USA

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.

Colombian emeralds – internal and external growth and dissolution features

Emeralds from Colombia are among the most highly-prized and valuable gemstones. Their growth phenomena including information about the geology of the area were described in detail by Pig-natelli et al. (2015, 2022) and Schmetzer and Martayan (2023). Here, we present data obtained by scanning electron microscopy (SEM), electron microprobe analysis (EMPA), and infrared absorption spectroscopy (IR) for five emerald crystals. The surface of the crystals shows both, growth phe-nomena as well as dissolution phenomena, the latter as etch pits (EP). Such EP have been used previously for other beryl types, mainly from pegmatitic environments (Kurumathoor and Franz, 2018); the Colombian emeralds come from low-grade metamorphosed black shales and thus offer the possibility to extend the use of EP as a provenance indicator to other types of beryl deposits. Internal structures are manifested in chemical zoning, investigated by EMPA and micro-X-ray fluo-rescence (µXRF). The crystals are characterized chemically by EMPA, polarized IR spectroscopy of oriented crystals showed the presence of fluids in the channels of the beryl structure.

Deep electromagnetic sounding for mineral exploration: LOTEM Validation Study 2017

Although the exploitation of strategic important mineral deposits is currently feasible down to a depth of ~ 1000 m, the extension of ore deposits in Germany is poorly known. The BMBF funded DESMEX (Deep Electromagnetic Sounding for Mineral Exploration) project focuses on the development of an electromagnetic exploration system which can be used for the exploration of mineral resources for depths down to 1000 m. The main focus lies in the exploration of potential mineral deposits in Germany. Ore mineralization leads to an increase of electrical conductivity in the host rock. Therefore, innovative methods are developed, which are able to image zones of high conductivity with respect to the intended exploration depth and deliver insights in the geometry of the ore deposit. In order to obtain an high coverage as well as an high resolution, air borne and ground based methods are combined in a semi airborne controlled source EM (CSEM) concept. This concept was tested in an old antimony mining area in eastern Thuringia. In the framework of DESMEX, the University of Cologne carried out ground based (long offset) transient-electromagnetic (LOTEM) measurements. Within the LOTEM validation study, an independent resistivity model of the survey area was derived, which serves as reference model for the semi airborne concept and is integrated in a final mineral deposition model. This data publication (https://doi.org/10.5880/GIPP-MT.201716.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Deep electromagnetic sounding for mineral exploration: LOTEM Validation Study 2016

Although the exploitation of strategic important mineral deposits is currently feasible down to a depth of ~ 1000 m, the extension of ore deposits in Germany is poorly known. The BMBF funded DESMEX (Deep Electromagnetic Sounding for Mineral Exploration) project focuses on the development of an electromagnetic exploration system which can be used for the exploration of mineral resources for depths down to 1000 m. The main focus lies in the exploration of potential mineral deposits in Germany. Ore mineralization leads to an increase of electrical conductivity in the host rock. Therefore, innovative methods are developed, which are able to image zones of high conductivity with respect to the intended exploration depth and deliver insights in the geometry of the ore deposit. In order to obtain an high coverage as well as an high resolution, air borne and ground based methods are combined in a semi airborne controlled source EM (CSEM) concept. This concept was tested in an old antimony mining area in eastern Thuringia. In the framework of DESMEX, the University of Cologne carried out ground based (long offset) transient-electromagnetic (LOTEM) measurements. Within the LOTEM validation study, an independent resistivity model of the survey area was derived, which serves as reference model for the semi airborne concept and is integrated in a final mineral deposition model. This data publication (https://doi.org/10.5880/GIPP-MT.201608.1) encompasses a detailed report in pdf format with a description of the project, information on the experimental setup, data collection, instrumentation used, recording configuration and data quality. The folder structure and content of the data repository are described in detail in Ritter et al. (2019). Time-series data are provided in EMERALD format (Ritter et al., 2015).

Mineral spectra and chemistry of 20 copper bearing minerals

The data set contains mineral chemical analyses of 20 different copper bearing minerals and their corresponding hyperspectral spectra. The hyperspectral data were acquired with the HySpex system in a range of 400 – 2500 nm and are presented in a spectral library. Detailed information about the mineral specimen, sample area and geochemistry is presented in the data sheets and associated data description. The spectral library presented here is part of a bigger collection of spectral libraries including samples from rare-earth minerals, rare-earth-oxides (Koerting et al., 2019a, http://doi.org/10.5880/GFZ.1.4.2019.004) and field samples from a copper-gold-pyrite mine in the Republic of Cyprus (Koerting et al., 2019b, http://doi.org/10.5880/GFZ.1.4.2019.005).

3D Simulation von Gashydratlagerstätten^SUGAR-Submarine Gashydrat-Ressourcen; SUGAR-A: Submarine Gashydrat-Lagerstätten als Deponie für die CO2-Sequestrierung - Sonderprogramm GEOTECHNOLOGIEN, Prospektion und Exploration von Gashydrat-Lagerstätten

Die Untersuchungen im Rahmen des Projektes SUGAR zielen darauf ab, in einem konzertierten Verbund von nationalen Industriepartnern und führenden Forschungseinrichtungen neue Ansätze, Geräte und technische Verfahren zur Erkundung von Hydrat-Lagerstätten am Meeresboden und Konzepte für die Speicherung von Kohlendioxid in marinen Sedimenten zu entwickeln. Der in SUGAR-A behandelte Themenkomplex zur Exploration von Gashydratvorkommen ergänzt die vom BMWi geförderten Arbeiten zum Abbau von submarinen Gashydratvorkommen und Transport von Erdgas (SUGAR-B); die gesamte potentielle Hydratverwertungskette wird erfasst und um Aspekte einer umweltverträglichen Lagerung des Klimagases Kohlendioxid erweitert. Das IfM GEOMAR plant im Rahmen des Verbundvorhabens die Entwicklung neuer Visualisierungs- und Datenverarbeitungstechniken sowie neuer Algorithmen, die eine Erkennung von Gasblasen in der Wassersäule deutlich verbessern und damit eine signifikant verbesserte Erkundung von Methanhydraten ermöglichen. Ziel der Fa. SEND ist es, in Deutschland die Systemtechnologie für tief geschleppte Streamer (DTMCS) zu etablieren. Im Vorhaben der IES GmbH soll die Bildung von Methanclathraten und ihre räumliche Verteilung in klastischen Ablagerungen am Kontinentalhang umfassend quantifiziert und modelliert sowie Algorithmen und Computerapplikationen zur Auswertung verfügbarer Datensätze entwickelt werden. Aufgabe der Fa. L-3 Communications ELAC Nautik GmbH ist die Entwicklung neuer Visualisierungs- und Datenverarbeitungstechniken sowie von neuen Algorithmen, die eine Erkennung von Gasblasen in der Wassersäule deutlich verbessern und damit eine signifikant verbesserte Erkundung von Methanhydraten ermöglichen. Die BGR Hannover ist für die Bewertung submariner Methanhydratvorkommen mit elektromagnetischen Verfahren zuständig. Die Verteilung (insbesondere die laterale Variationen) und Konzentration der Klathrate in der Sedimentmatrix ist für eine Abschätzung der Höffigkeit von Vorkommen von Interesse. (Text gekürzt)

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