Marcel Guillong

Last Name

Guillong

First Name

Marcel

ORCID

0000-0002-6920-3362

Organisational unit

03958 - Bachmann, Olivier / Bachmann, Olivier

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Publications1 - 10 of 141

Evidence for a spike in mantle carbon outgassing during the Ediacaran period
Paulsen, Timothy; Deering, Chad; Sliwinski, Jakub; et al. (2017)
Nature Geoscience
Long-term cycles in Earth’s climate are thought to be primarily controlled by changes in atmospheric CO2 concentrations. Changes in carbon emissions from volcanic activity can create an imbalance in the carbon cycle. Large-scale changes in volcanic activity have been inferred from proxies such as the age abundance of detrital zircons, but the magnitude of carbon emissions depends on the style of volcanism as well as the amount. Here we analyse U–Pb age and trace element data of detrital zircons from Antarctica and compare the results with the global rock record. We identify a spike in CO2-rich carbonatite and alkaline magmatism during the Ediacaran period. Before the Ediacaran, secular cooling of the mantle and the advent of cooler subduction regimes promoted the sequestration of carbon derived from decarbonation of subducting oceanic slabs in the mantle. We infer that subsequent magmatism led to the extensive release of carbon that may at least in part be recorded in the Shuram–Wonoka carbon isotope excursion. We therefore suggest that this pulse of alkaline volcanism reflects a profound reorganization of the Neoproterozoic deep and surface carbon cycles and promoted planetary warming before the Cambrian radiation.
Revealing exhumation of the central Alps during the Early Oligocene by detrital zircon U-Pb age and fission-track double dating in the Taveyannaz Formation
Lu, Gang; Fellin, Maria Giuditta; Winkler, Wilfried; et al. (2020)
International Journal of Earth Sciences
The late Eocene-to-early Oligocene Taveyannaz Formation is a turbidite series deposited in the Northern Alpine Foreland Basin (close to the Alpine orogenic front). Double dating of zircons with the fission-track and the U-Pb methods is applied on samples from the Taveyannaz Formation to reconstruct the exhumation history of the Central-Western Alps and to understand the syn-collisional magmatism along the Periadriatic lineament. Three samples from this unit show similar detrital zircon fission-track age populations that center at: 33-40 Ma (20%); 69-92 Ma (30-40%); and 138-239 Ma (40-50%). The youngest population contains both syn-volcanic and basement grains. Combined with zircon U-Pb data, it suggests that the basement rocks of Apulian-affinity nappes (Margna Sesia, Austroalpine) were the major sources of detritus, together with the Ivrea Zone and recycled Prealpine flysch, that contributed debris to the Northern Alpine Foreland Basin. Furthermore, the rocks of the Sesia-Lanzo Zone or of equivalent units exposed at that time presumably provided the youngest basement zircon fission-track ages to the basin. The Biella volcanic suite was the source of volcanogenic zircons. Oligocene sediment pathways from source to sink crossed further crystalline basement units and sedimentary covers before entering the basin from the southeast. The lag times of the youngest basement age populations (volcanic zircons excluded) are about 11 Myr. This constrains average moderate-to-high exhumation rate of 0.5-0.6 km/Myr in the pro-side of the orogenic wedge of the Central Alps during the late Eocene to early Oligocene.
Evaluating the Potential of Rhyolitic Glass as a Lithium Source for Brine Deposits
Ellis, Ben S.; Szymanowski, Dawid; Harris, Chris; et al. (2022)
Economic Geology
Lithium is an economically important element that is increasingly extracted from brines accumulated in continental basins. While a number of studies have identified silicic magmatic rocks as the ultimate source of dissolved brine lithium, the processes by which Li is mobilized remain poorly constrained. Here we focus on the potential of low-temperature, post-eruptive processes to remove Li from volcanic glass and generate Li-rich fluids. The rhyolitic glasses in this study (from the Yellowstone-Snake River Plain volcanic province in western North America) have interacted with meteoric water emplacement as revealed by textures and a variety of geochemical and isotopic signatures. Indices of glass hydration correlate with Li concentrations, suggesting Li is lost to the water during the water-rock interaction. We estimate the original Li content upon deposition and the magnitude of Li depletion both by direct in situ glass measurements and by applying a partition-coefficient approach to plagioclase Li contents. Across our whole sample set (19 eruptive units spanning ca. 10 m.y.), Li losses average 8.9 ppm, with a maximum loss of 37.5 ppm. This allows estimation of the dense rock equivalent of silicic volcanic lithologies required to potentially source a brine deposit. Our data indicate that surficial processes occurring post-eruption may provide sufficient Li to form economic deposits. We found no relationship between deposit age and Li loss, i.e., hydration does not appear to be an ongoing process. Rather, it occurs primarily while the deposit is cooling shortly after eruption, with δ18O and δD in our case study suggesting a temperature window of 40° to 70°C.
Mid-Miocene silicic explosive volcanism of the Tokaj Mts., eastern-central Europe: eruption chronology, geochemical fingerprints and petrogenesis
Lukács, Réka; Guillong, Marcel; Szepesi, János; et al. (2024)
Gondwana Research
The Tokaj Mts. volcanism occurred in a thinning continental lithosphere regime at the final stage of the subduction process. Using high-precision zircon U-Pb dating, four major explosive eruption events were distinguished. Among them the 13.1 Ma Sátoraljaújhely and the 12.0 Ma Szerencs eruptions could have yielded large amount of volcanic material (possibly > 100 km3) and they were associated with caldera collapse as shown by the several hundred-metre-thick pyroclastic deposits and the long (>100 km) runout pyroclastic flow in case of the 13.1 Ma eruption. The 12.3 Ma Hegyköz and the 11.6 Ma Vizsoly eruptions were relatively smaller. The volcanic products can be readily distinguished by zircon and glass trace elements and trace element ratios, which can be used for fingerprinting and to correlate with distal deposits. The Rb, Ba, Sr content and strong negative Eu-anomaly of the glasses reflect extreme crystal fractionation, particularly for the Szerencs rhyolitic magma. The silicic volcanic products of the Tokaj Mts. show compositional similarities with the so-called ‘dry–reduced–hot’ rhyolite type consistent with an origin in an extensional environment, where the primary magmas were formed by near-adiabatic decompression melting in the mantle with subordinate fluid flux. In contrast, some of the older Bükkalja rhyolitic magmas evolved via more hydrous evolutionary paths, where amphibole played a role in the control of the trace element budget. The significant increase of zircon ε Hf values from −8.8 to + 0.2 in the rhyolitic pyroclastic rocks of Tokaj Mts. with time implies that mantle-derived magmas became more dominant. This can be explained by the specific tectonic setting, i.e. the final stage of subduction when the descending subducted slab became almost vertical, which exerted a pull in the upper lithosphere leading to thinning and accelerated subsidence as well as asthenospheric mantle flow just before the slab detachment.
LA-ICP-MS U-Pb zircon geochronology data of the Early to Mid-Miocene syn-extensional massive silicic volcanism in the Pannonian Basin (East-Central Europe)
Lukács, Réka; Guillong, Marcel; Sliwinski, Jakub; et al. (2018)
Data in Brief
Correction to: Magmatic and tectonic history of Jurassic ophiolites and associated granitoids from the South Apuseni Mountains (Romania)
Seghedi, Ioan; Gallhofer, Daniela; von Quadt, Albrecht; et al. (2018)
Swiss Journal of Geosciences
Mica Rb-Sr dating by laser ablation ICP-MS/MS using an isochronous calibration material and application to West African kimberlites
Giuliani, Andrea; Oesch, Senan; Guillong, Marcel; et al. (2024)
Chemical Geology
In-situ Rb-Sr dating of mica by laser ablation ICP-MS/MS has recently emerged as a new tool to date a range of geological processes including magmatic, metamorphic and hydrothermal events. The majority of age results presented to date are based on Rb/Sr calibration using the MicaMG pressed nano-powder pellet. However, some studies have reported low accuracy associated with mica Rb-Sr ages using this method, which are attributed to the different ablation properties of MicaMG and natural mica. In this work, we document the results of a systematic comparison between isotope-dilution and laser -ablation Rb/Sr ages of micas in Cretaceous diamondiferous kimberlites from Bultfontein (South Africa), Koidu and Tonguma (Sierra Leone), with additional in-situ data for the Mt. Dromedary mica (Australia). We adopt two different analytical strategies. While NIST610 SRM is employed to calibrate 87Sr/86Sr in both cases, the first approach follows the convention to utilise MicaMG as calibration material for Rb/Sr. In the second approach, Rb/Sr quantification is initially undertaken with NIST610, with a subsequent correction for Rb/Sr offset based on the age of isochronous micas (WBLK) from the Cretaceous Wimbledon lamproite (South Africa). We show that, using our instrumental set -up, employment of MicaMG as Rb/Sr calibration material commonly provides inaccurate results (generally 5-10% older than the solution -based ages). Conversely, our new approach returns accurate ages (within 3%) and represents a promising avenue to improve the accuracy of mica Rb-Sr age by laser ablation ICP-MS/MS especially once isochronous mica reference materials will be developed. Application of this methodology to multiple samples from Koidu and Tonguma shows that, contrarily to previous inferences based on age-dating of fewer samples, magmatism occurred at both localities in the 145-151 Ma interval. After a temporal hiatus, magmatism restarted exclusively in the Tonguma cluster between 135 and 139 Ma. The relative volumetric importance of these two magmatic stages in the Tonguma diamond mine awaits further evaluation.
Sulfide-associated hydrothermal dolomite and calcite reveal a shallow burial depth for Alpine-type Zn-(Pb) deposits
Giorno, Michele; Barale, Luca; Bertok, Carlo; et al. (2022)
Geology
Difficulties in dating Mississippi Valley–type (MVT) mineral deposits and the often closely associated dolomitization have led to controversy regarding their origin. We report the first radiometric ages for the Gorno mining district in northern Italy, an example of the Alpine subclass of MVT deposits. U-Pb ages of hydrothermal carbonates pre and postdating the ore-forming event show that base-metal mineralization occurred shortly after the deposition of the Carnian host rocks. This implies that the Gorno ore deposits formed at shallow burial depth prior to the Early Jurassic western Tethys rifting phase. Contemporaneous Triassic magmatism and extensional tectonics likely contributed to the high geothermal heat fluxes required to drive the mineralizing system. Our study reinforces the need for reliable geochronological data for metallogenic models and warns against a general application of classic North American MVT models to similar deposits worldwide.
The evolution of a magmatic plumbing system from inception to extinction: The case of the Aegina magmatic province (Greece)
Müller, Michelle; Popa, Răzvan-Gabriel; Schierscher, Sophie; et al. (2026)
Earth and Planetary Science Letters
The Aegina Magmatic Province, located within the South Aegean Volcanic Arc, is offering a unique window into the evolution of a magmatic plumbing system in a subduction zone, from inception to extinction. This study examines the entire volcanic life cycle of the province utilizing zircon U-Pb geochronology and extensive geochemical data on multiple samples to uncover the factors that influence magma compositions, reservoir evolution, and eruptability during the area's magmatic lifespan. The volcanic system was active for approximately 2.5 My, with the first eruptions beginning around 4.3 Ma, after a prolonged phase of magma reservoir nucleation and growth in the crust lasting over 0.5 My. This nucleation period did not produce eruptions and was identifiable only by zircon antecrysts found in the subsequent deposits. The volcanic history includes two distinct eruptive phases characterized by having different eruption frequencies. Mineral chemistry indicates stable upper-crustal storage conditions, at around 2 kbar, throughout Aegina's lifetime. However, significant temperature and water content fluctuations were linked to magma recharge events. Initially, the recharge involved hydrous, volatile-rich magmas, which facilitated crustal magma storage and differentiation to andesitic/dacitic compositions, resulting in intermittent eruptions of these intermediate compositions as crystal-rich lava domes. Over time, the influx of drier magmas (< 4 wt.% dissolved H₂O) increased, leading to more frequent eruptions and a progressive dilution of volatiles in the upper-crustal reservoir. This trend towards drier magma continued into the final phase, with the last eruptions (around 2.1 Ma) being characterized by dry, crystal-poor basaltic andesites (< 3 wt.% dissolved H₂O). This drying out trend towards the cessation of magmatic activity may indicate a progressively depleted mantle source under Aegina, and a transition to magmatic activity more to the South, in the region of the presently active Peninsula of Methana.
In-situ Rb-Sr dating of mica: method refinement and application to mineral resources
Giuliani, Andrea; Guillong, Marcel; Oesch, Senan; et al. (2023)
Proceedings of the 17th SGA Biennial Meeting. Volume 3
In-situ Rb-Sr dating of mica by laser ablation ICP-MS/MS has recently emerged as a new tool to date a range of geological processes including mineralisation events. The majority of age results presented to date are based on Rb/Sr calibration using the widely available MicaMG pressed-powder pellet. However, several studies have reported low accuracy associated with mica Rb-Sr ages using this method or large variations in calculated Rb/Sr for the same mica attributed to the different ablation properties of MicaMG and natural mica. In this work, we first report the results of a systematic comparison between isotope-dilution and in-situ Rb/Sr ages of micas in diamondiferous kimberlites from South Africa and Sierra Leone. We confirm that employment of MicaMG as calibration material may provide inaccurate results and present a new approach to obtain accurate ages, which relies on Rb/Sr calibration using the synthetic glass NIST610 SRM and an in-house mica standard. This updated procedure is then employed to constrain the ages of other diamond deposits and address the formation of Au mineralisation in the Eastern Goldfields (Australia).

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Marcel Guillong

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