Danilo Di Genova

Danilo Di Genova
University of Bayreuth · Bayerisches Geoinstitute

PhD

About

82
Publications
15,530
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
829
Citations
Additional affiliations
March 2020 - present
University of Bayreuth
Position
  • Akademischer Rat
July 2018 - February 2020
Technische Universität Clausthal
Position
  • Research Associate
October 2016 - June 2018
University of Bristol
Position
  • Research Associate

Publications

Publications (82)
Article
Full-text available
The most viscous volcanic melts and the largest explosive eruptions on our planet consist of calcalkaline rhyolites. These eruptions have the potential to influence global climate. The eruptive products are commonly very crystal-poor and highly degassed, yet the magma is mostly stored as crystal mushes containing small amounts of interstitial melt...
Article
Traditionally depicted as homogeneous materials, manmade and volcanic glasses are often subjected to nanostructuration during demixing and crystallization of their parental melt. While the controlled formation of nanocrystals has been exploited for decades in the industrial production of glass-ceramics to obtain materials with superior properties,...
Article
Full-text available
Although gas exsolution is a major driving force behind explosive volcanic eruptions, viscosity is critical in controlling the escape of bubbles and switching between explosive and effusive behavior. Temperature and composition control melt viscosity, but crystallization above a critical volume (>30 volume %) can lock up the magma, triggering an ex...
Article
Full-text available
The numerical modelling of magma transport and volcanic eruptions requires accurate knowledge of the viscosity of magmatic liquids as a function of temperature and melt composition. However, there is growing evidence that volcanic melts can be prone to nanoscale modification and crystallization before and during viscosity measurements. This challen...
Preprint
Full-text available
Viscosity is of great importance in governing the dynamics of volcanoes, including their eruptive style. The viscosity of a volcanic melt is dominated by temperature and chemical composition, both oxides and water content. The changes in melt structure resulting from the interactions between the various chemical components are complex, and the cons...
Article
Full-text available
The majority of basaltic magmas stall in the Earth’s crust as a result of the rheological evolution caused by crystallization during transport. However, the relationships between crystallinity, rheology and eruptibility remain uncertain because it is difficult to observe dynamic magma crystallization in real time. Here, we present in-situ 4D data f...
Conference Paper
Full-text available
The knowledge of the viscosity of magmas as a function of melt composition and temperature is central in the numerical modeling of the magmatic dynamics and eruptive scenarios. Recent studies suggest that the measure of the viscosity of volcanic melts is affected by the occurrence of nano-scale modification (i.e., crystallization) of the melt struc...
Article
Full-text available
Volcanic materials can experience up to eleven orders of magnitude of cooling rate (qc) starting from 10–5 K s⁻¹. The glassy component of volcanic material is routinely measured via differential scanning calorimeter (DSC) to obtain qc through the determination of the glass fictive temperature (Tf). Conventional DSC (C-DSC), which has been employed...
Article
Experimental and spectroscopic investigation of glasses synthesized at high pressure provides fundamental information about the structure/physical properties relationships of these materials. However, glass synthesis in conventional large-volume high-pressure devices is limited by the achievable quenching rates. This study reports the first success...
Article
Full-text available
The viscosity of volcanic melts is a dominant factor in controlling the fluid dynamics of magmas and thereby eruption style. It can vary by several orders of magnitude, depending on temperature, chemical composition, and water content. The experimentally accessible temperature range is restricted by melt crystallization and gas exsolution. Therefor...
Article
Full-text available
The numerical modelling of magma transport and volcanic eruptions requires accurate knowledge of the viscosity of magmatic liquids as a function of temperature and melt composition. However, there is growing evidence that volcanic melts can be prone to nanoscale modification and crystallization before and during viscosity measurements. This challen...
Article
Crystallisation is a complex process that significantly affects the rheology of magma, and thus the flow dynamics during a volcanic eruption. For example, the evolution of crystal fraction, size and shape has a strong impact on the surface crust formation of a lava flow, and accessing such information is essential for accurate modelling of lava flo...
Article
Full-text available
The iron coordination, its oxidation state (Fe²⁺/Fetot.), and alkali ratio [Na/(Na + K)] greatly influence the structure and thus the viscosity of volcanic melts, which is known to play a key role in the dynamics of volcanic eruptions. Furthermore, it has been recently reported that volcanic melts can contain iron-bearing nanocrystals and this make...
Article
Full-text available
The dichotomy between explosive volcanic eruptions, which produce pyroclasts, and effusive eruptions, which produce lava, is defined by the presence or absence of fragmentation during magma ascent. For lava fountains the distinction is unclear, since the liquid phase in the rising magma may remain continuous to the vent, fragment in the fountain, t...
Article
Full-text available
Many of the grand challenges in volcanic and magmatic research are focused on understanding the dynamics of highly heterogeneous systems and the critical conditions that enable magmas to move or eruptions to initiate. From the formation and development of magma reservoirs, through propagation and arrest of magma, to the conditions in the conduit, g...
Article
Full-text available
Quantifying the oxidation state of multivalent elements in silicate melts (e.g., Fe2+ versus Fe3+ or S2- versus S6+) is fundamental for constraining oxygen fugacity. Oxygen fugacity is a key thermodynamic parameter in understanding melt chemical history from the Earth’s mantle through the crust to the surface. To make these measurements, analyses a...
Conference Paper
Full-text available
Quantifying the oxidation state of multivalent elements in silicate melts (e.g., Fe²⁺ versus Fe³⁺ or S²⁻ versus S⁶⁺) is fundamental for constraining oxygen fugacity. Oxygen fugacity is a key thermodynamic parameter in understanding melt chemical history from the Earth's mantle through the crust to the surface. To make these measurements, analyses a...
Article
A gap in viscosity data spreads between glass transition and liquidus temperature for glass compositions, which are prone to crystallization. Alternatively, differential scanning calorimetry (DSC) is used to calculate viscosity as both the cooling rate in a DSC experiment and the shear viscosity at the fictive temperature are related by a constant...
Article
Full-text available
Basaltic eruptions are the most common form of volcanism on Earth and planetary bodies. The low viscosity of basaltic magmas inhibits fragmentation, which favours effusive and lava-fountaining activity, yet highly explosive, hazardous basaltic eruptions occur. The processes that promote fragmentation of basaltic magma remain unclear and are subject...
Article
Full-text available
The Masaya Triple Layer tephra was deposited ~2100 years ago during a basaltic Plinian eruption of Masaya caldera, Nicaragua, and is one of few known examples of this extreme endmember of basaltic explosive volcanism. Masaya caldera is located approximately 25 km from Managua, the capital of Nicaragua, and a Plinian eruption presents a high potenti...
Article
The physical properties of silicate melts are of critical importance for understanding magmatic and volcanic processes on Earth and other planets. Most physical properties of melts are, ultimately, a consequence of the structural organization of the melt. Robust and fully generalizable strategies for the prediction of properties of naturally occurr...
Article
Plinian-type eruptions are extremely hazardous, producing pyroclastic fallout and flows extending many kilometres from the vent. The most commonly invoked eruption trigger for Plinian-type eruptions is the intrusion of fresh magma, generally associated with precursory ground deformation and seismicity days/weeks before eruption. Closed-system inter...
Research
The low viscosity of basaltic magmas generally favours effusive and mildly explosive volcanic activity. Highly explosive basaltic eruptions occur less frequently and their eruption mechanism still remains subject to debate [1] [2] [3] [4], with implications for the significant hazard associated with explosive basaltic volcanism. Particularly, highl...
Article
Analysis of Redox Changes in Silicate Glasses Using EPMA and Raman Spectroscopy - Volume 24 Supplement - Ery C Hughes, Ben Buse, Stuart L Kearns, Danilo Di Genova, Jon D Blundy
Article
Full-text available
Iron and water content substantially affect the physical properties of natural silicate melts and may, therefore, influence magmatic and volcanic processes such as crystallization, degassing, flow behaviour and eruptive style. Here we present Raman spectroscopic data for a set of synthetic and natural multicomponent glasses with varying iron oxidat...
Conference Paper
Full-text available
Iron is a fundamental component of natural silicate melts and glasses and its structural role in magmas can drastically affect the melt's rheology. It has recently been shown that iron may crystallize out of the magma to form nanolites, effectively depleting the residual melt of iron and bringing forth changes in melt structure and viscosity. This,...
Conference Paper
Full-text available
A thermo-mechanical rig (P2R) is being developed to replicate on a synchrotron the conditions of pressure (P), temperature (T), oxygen fugacity (fO2) and volatile content that magmas experience during eruptions. Using synchrotron X-ray tomography (sCT), this innovative technology will allow us to directly capture and quantify the kinetics of both d...
Article
Magmatic sulfide minerals preserved in fresh volcanic rocks can be used to trace sulfur and chalcophile element evolution in magmatic systems and to constrain the potential magmatic contribution to ore-forming fluids. In this work, we present a petrographic and microanalytical study of magmatic sulfides in the products of La Fossa (Vulcano, souther...
Article
Full-text available
Magma crystallisation is a fundamental process driving eruptions and controlling the style of volcanic activity. Crystal nucleation delay, heterogeneous and homogeneous nucleation and crystal growth are all time-dependent processes, however, there is a paucity of real-time experimental data on crystal nucleation and growth kinetics, particularly at...
Article
Full-text available
The iron oxidation state in silicate melts is important for understanding their physical properties, although it is most often used to estimate the oxygen fugacity of magmatic systems. Often high spatial resolution analyses are required, yet the available techniques, such as μXANES and μMössbauer, require synchrotron access. The Flank Method is an...
Article
Full-text available
Storage and transport of silicate melts in the Earth's crust and their emplacement on the planet's surface occur almost exclusively at sub-liquidus temperatures. At these conditions, the melts undergo crystallization under a wide range of cooling-rates, deformation-rates, and oxygen fugacities (fO2). Oxygen fugacity is known to influence the thermo...
Article
Full-text available
ABSTRACT The effect of iron content and iron nanolites on Raman spectra of hydrous geologically-relevant glasses is pre- sented. Current procedures to estimate the water content using Raman spectra were tested to explore potential effects of iron content, its oxidation state, and nanolites on models' reliability. A chemical interval spanning from b...
Conference Paper
The structure of silicate melt governs its viscosity, which influences its transport, degassing rate and, ultimately, eruption style of volcanoes. Raman spectroscopy can provide insights into the melt structure and recent studies have shown that correlations between Raman spectra of glasses and melt viscosity can be established. However, so far, th...
Article
Full-text available
Hydrothermal quartz crystals, which occur in the Rusey Fault Zone (Cornwall, UK), show feathery textures and network-like filamentous textures. Optical hot-cathodoluminescence (CL) analysis and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) investigations on quartz samples revealed that positions exhibiting feathery texture...
Article
Full-text available
Raman spectrometers will form a key component of the analytical suite of future planetary rovers intended to investigate geological processes on Mars. In order to expand the applicability of these spectrometers and use them as analytical tools for the investigation of silicate glasses, a database correlating Raman spectra to glass composition is cr...
Conference Paper
Full-text available
We present a study on the systematic changes of Raman spectra of a series of glasses as a function of their chemistry. These glass compositions are considered as analogues for rock materials identified on Mars. We performed a diffusion experiment between an iron-rich basaltic and a rhyolitic melt under reducing conditions to produce a wide range of...
Conference Paper
Full-text available
Experimental volcanology is a powerful tool to reconstruct the dynamics of magmatic fluids within the conduit. More specifically analogue models, allow constraining the conduit dynamics by independently examine physical variables and their reciprocal relationships. Accurate scaling of the experiments to the natural systems is necessary to derive qu...
Article
A high-temperature rheometer equipped with a graphite furnace, characterized by an air-bearing-supported synchronous motor, has been enhanced by a custom-made Pt-Au concentric cylinder assembly. With this adaptation, viscosity measurements of highly fluid melts can be achieved at high temperatures, up to 1273 K. Due to the air-bearing-supported mo...
Article
To develop Raman spectroscopy as a quantitative tool in both geosciences and planetary sciences the effect of iron oxidation state (Fe3+/Fetot) on the Raman spectra of basaltic and pantelleritic glasses has been investigated. We have used remelted pantellerite from Pantelleria Island and synthetic iron-rich basaltic glasses [from Chevrel et al. (20...
Article
Full-text available
The degassing kinetics of ascending magma strongly affect eruption dynamics. The kinetics are in turn influenced by magma properties. The investigation of the relationship between magma properties and eruption dynamics is a key element in revealing the processes characterizing magmatic flows within the shallow conduit. To explore the effects of phy...
Article
Full-text available
The specific heat capacity (Cp) of six variably hydrated (~3.5 wt% H2O) iron-bearing Etna trachybasaltic glasses and liquids has been measured using differential scanning calorimetry from room temperature across the glass transition region. These data are compared to heat capacity measurements on thirteen melt compositions in the iron-free anorthit...
Article
Full-text available
The effect of chemical composition on the Raman spectra of a series of natural calcalkaline silicate glasses has been quantified by performing electron microprobe analyses and obtaining Raman spectra on glassy filaments (~450 μm) derived from a magma mingling experiment. The results provide a robust compositionally-dependent database for the Raman...
Research
Full-text available
Here we present the calibration of the rheometer and the results of a rheological characterization study on a series of very low viscous synthetic and natural carbonatitic melts at different oxygen fugacity (air and CO2 saturated atmosphere).
Research
Full-text available
In this study we combine chemical analysis from magma mixing experiments between remelted basaltic and rhyolitic melts, with a high spatial resolution Raman spectroscopy investigation; we focus on tracking the evolution of the Raman spectrum with chemical composition of silicate glasses. The evolution of the acquired Raman spectra with the measured...
Conference Paper
Full-text available
We performed decompression experiments in a shock tube system. Silicon oil was used as a proxy for basaltic melt, and saturated with 10 MPa of Argon for 72h, then slowly decompressed under controlled conditions. The dynamics of exsolved volatiles were studied through video image analysis, supported by recordings of the pressure state within the sys...
Conference Paper
Full-text available
Raman spectroscopy is a spectroscopic technique based on inelastic scattering of monochromatic light which provides information about molecular vibrations of the investigated sample. Since the discovery of the Raman Effect (1928) in scattered light from liquids, the Raman investigation has been extended to a large number of substances at different...