Logo: to the web site of Uppsala University

uu.sePublications from Uppsala University
Change search
Link to record
Permanent link

Direct link
Alternative names
Publications (10 of 189) Show all publications
Dayton, K., Gazel, E., Wieser, P., Troll, V. R., Carracedo, J. C., La Madrid, H., . . . Perez-Torrado, F. J. (2023). Deep magma storage during the 2021 La Palma eruption. Science Advances, 9(6), Article ID eade7641.
Open this publication in new window or tab >>Deep magma storage during the 2021 La Palma eruption
Show others...
2023 (English)In: Science Advances, E-ISSN 2375-2548, Vol. 9, no 6, article id eade7641Article in journal (Refereed) Published
Abstract [en]

The 2021 La Palma eruption provided an unpreceded opportunity to test the relationship between earthquake hypocenters and the location of magma reservoirs. We performed density measurements on CO2-rich fluid in-clusions (FIs) hosted in olivine crystals that are highly sensitive to pressure via calibrated Raman spectroscopy. This technique can revolutionize our knowledge of magma storage and transport during an ongoing eruption, given that it can produce precise magma storage depth constraints in near real time with minimal sample prep-aration. Our FIs have CO2 recorded densities from 0.73 to 0.98 g/cm3, translating into depths of 15 to 27 km, which falls within the reported deep seismic zone recording the main melt storage reservoir.

Place, publisher, year, edition, pages
American Association for the Advancement of Science (AAAS)American Association for the Advancement of Science, 2023
National Category
Geochemistry
Identifiers
urn:nbn:se:uu:diva-499939 (URN)10.1126/sciadv.ade7641 (DOI)000937229100009 ()36753542 (PubMedID)
Available from: 2023-04-06 Created: 2023-04-06 Last updated: 2024-01-15Bibliographically approved
Barker, A., Magnusson, E., Troll, V. R., Harris, C., Mattsson, H. B., Holm, P., . . . Deegan, F. (2023). Disequilibrium in historic volcanic rocks from Fogo, Cape Verde traces carbonatite metasomatism of recycled ocean crust. Lithos, 107328-107328, Article ID 107328.
Open this publication in new window or tab >>Disequilibrium in historic volcanic rocks from Fogo, Cape Verde traces carbonatite metasomatism of recycled ocean crust
Show others...
2023 (English)In: Lithos, ISSN 0024-4937, E-ISSN 1872-6143, p. 107328-107328, article id 107328Article in journal (Refereed) Published
Abstract [en]

Fogo, Cape Verde, located upon thick oceanic lithosphere, provides a window into processes occurring in the mantle where recycled ocean crust in an upwelling mantle plume interacts with ambient mantle. Our objective is to investigate the nature of the lithologies of the mantle sources involved in the petrogenesis of historic volcanic rocks from Fogo. We observe enclaves and mingling textures in the lavas combined with oxygen isotope disequilibrium between olivine and clinopyroxene phenocrysts. Olivine δ18O values display positive correlations with Zr/Hf and Zr/Y and a negative correlation with U/Th, whereas clinopyroxene δ 18O values correlate positively with Ba/Nb. Heterogeneity between crystal populations and within the groundmass indicates that multiple magma batches are mixed beneath Fogo. In terms of mantle endmembers and source lithologies, a HIMU endmember was generated by melting of carbonated eclogite as indicated by low δ 18O values, Zr/Hf, Ba/Nb and high U/Th ratios. In contrast, we show the EM1 endmember has high δ 18O, Zr/Hf, Ba/Nb and low U/Th ratios, derived from melting of variably carbonated peridotite. Additionally, Ba/Th ratio are high, indicating that carbonatite melts have contributed to alkaline magma compositions at Fogo.

Place, publisher, year, edition, pages
Elsevier, 2023
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-509766 (URN)10.1016/j.lithos.2023.107328 (DOI)001069081700001 ()
Funder
The Swedish Foundation for International Cooperation in Research and Higher Education (STINT)Swedish Research Council
Available from: 2023-08-22 Created: 2023-08-22 Last updated: 2023-10-05Bibliographically approved
Kereszturi, G., Heap, M., Schaefer, L. N., Darmawan, H., Deegan, F., Kennedy, B., . . . Walter, T. R. (2023). Porosity, strength, and alteration - Towards a new volcano stability assessment tool using VNIR-SWIR reflectance spectroscopy. Earth and Planetary Science Letters, 602, Article ID 117929.
Open this publication in new window or tab >>Porosity, strength, and alteration - Towards a new volcano stability assessment tool using VNIR-SWIR reflectance spectroscopy
Show others...
2023 (English)In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 602, article id 117929Article in journal (Refereed) Published
Abstract [en]

Volcano slope stability analysis is a critical component of volcanic hazard assessments and monitoring. However, traditional methods for assessing rock strength require physical samples of rock which may be difficult to obtain or characterize in bulk. Here, visible to shortwave infrared (350-2500 nm; VNIR-SWIR) reflected light spectroscopy on laboratory-tested rock samples from Ruapehu, Ohakuri, Whakaari, and Banks Peninsula (New Zealand), Merapi (Indonesia), Chaos Crags (USA), Styrian Basin (Austria) and La Soufriere de Guadeloupe (Eastern Caribbean) volcanoes was used to design a novel rapid chemometric-based method to estimate uniaxial compressive strength (UCS) and porosity. Our Partial Least Squares Regression models return moderate accuracies for both UCS and porosity, with R2 of 0.43-0.49 and Mean Absolute Percentage Error (MAPE) of 0.2-0.4. When laboratory-measured porosity is included with spectral data, UCS prediction reaches an R2 of 0.82 and MAPE of 0.11. Our models highlight that the observed changes in the UCS are coupled with subtle mineralogical changes due to hydrothermal alteration at wavelengths of 360-438, 532-597, 1405-1455, 2179-2272, 2332-2386, and 2460-2490 nm. These mineralogical changes include mineral replacement, precipitation hydrothermal alteration processes which impact the strength of volcanic rocks, such as mineral replacement, precipitation, and/or silicification. Our approach highlights that spectroscopy can provide a first order assessment of rock strength and/or porosity or be used to complement laboratory porosity-based predictive models. VNIR-SWIR spectroscopy therefore provides an accurate non-destructive way of assessing rock strength and alteration mineralogy, even from remote sensing platforms. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
uniaxial compressive strength, advanced argillic alteration, debris avalanche, phyllosilicates, hyperspectral remote sensing, hydrothermal alteration
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-492254 (URN)10.1016/j.epsl.2022.117929 (DOI)000896023200008 ()
Funder
Swedish Research Council
Available from: 2023-01-04 Created: 2023-01-04 Last updated: 2023-01-04Bibliographically approved
Gisbert, G., Troll, V. R., Day, J. M. D., Geiger, H., Perez-Torrado, F. J., Aulinas, M., . . . Carracedo, J. C. (2023). Reported ultra-low lava viscosities from the 2021 La Palma eruption are potentially biased [Letter to the editor]. Nature Communications, 14, Article ID 6453.
Open this publication in new window or tab >>Reported ultra-low lava viscosities from the 2021 La Palma eruption are potentially biased
Show others...
2023 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 14, article id 6453Article in journal, Letter (Refereed) Published
Place, publisher, year, edition, pages
Springer Nature, 2023
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-522400 (URN)10.1038/s41467-023-42022-x (DOI)001142518400007 ()37845237 (PubMedID)
Available from: 2024-02-05 Created: 2024-02-05 Last updated: 2024-02-05Bibliographically approved
Jägerup, S. B., Troll, V. R., Geiger, H., Deegan, F., Harris, C., Carracedo, J. C., . . . van der Zwan, F. M. (2023). Silicic frothy xenoliths (xeno-pumice) in recent volcanics from Gran Canaria, Canary Islands. Journal of Volcanology and Geothermal Research, 440, Article ID 107857.
Open this publication in new window or tab >>Silicic frothy xenoliths (xeno-pumice) in recent volcanics from Gran Canaria, Canary Islands
Show others...
2023 (English)In: Journal of Volcanology and Geothermal Research, ISSN 0377-0273, E-ISSN 1872-6097, Vol. 440, article id 107857Article in journal (Refereed) Published
Abstract [en]

The Quaternary small-volume alkaline magmatic episode on Gran Canaria erupted dominantly basanite and nephelinite lavas and scoria deposits that contain a range of mantle and crustal xenoliths. These xenoliths comprise peridotite nodules, partially melted plutonic and volcanic rock fragments, and a group of light colored, felsic, and commonly frothy quartz-bearing rock fragments (xeno-pumice) that show evidence for intense interaction with their host magmas. Here we study a selection of these felsic and, in part, glassy and vesicular xenoliths from North and North-East Gran Canaria, with the aim to unravel their ultimate origin and learn more about magma storage and ascent within and below the island. Inspection of textures, mineral assemblages and glass compositions reveal one group of felsic xenoliths with fresh to partly altered igneous phenocryst assemblages and relict magmatic textures in addition to 818O values of 3.6 to 6.6%o. This group is interpreted to be of igneous origin. A second group of frothy felsic xenoliths displays mineralogy and textural characteristics more similar to sedimentary rocks with frequent occurrence of quartz, a mineral usually not present as phenocrysts in magmatic rocks from the Canary Islands. This second group displays relatively high 818O values (8.1 to 16.8%o), more typical for sedimentary lithologies, and is thus interpreted to represent material derived from the extensive pre-island sedimentary part of the ocean crust. The investigated xenoliths from North Gran Canaria thus provide a snapshot of pre-island sedimentary geology as well as the island's "magmatic" interior. These new data help constrain the available subsurface compositional variations within and below the Canary Islands and will hence be useful in interpreting magma evolution trends and magma storage levels.

Place, publisher, year, edition, pages
Elsevier BV, 2023
Keywords
Gran Canaria, Alkaline volcanism, Xenoliths, Xeno-pumice, Magma-sediment interaction
National Category
Geology Geochemistry
Identifiers
urn:nbn:se:uu:diva-509271 (URN)10.1016/j.jvolgeores.2023.107857 (DOI)001040388000001 ()
Available from: 2023-08-23 Created: 2023-08-23 Last updated: 2023-08-23Bibliographically approved
Radu, I.-B., Skogby, H., Troll, V. R., Deegan, F. M., Geiger, H., Müller, D. & Thordarson, T. (2023). Water in clinopyroxene from the 2021 Geldingadalir eruption of the Fagradalsfjall Fires, SW-Iceland. Bulletin of Volcanology, 85(5), Article ID 31.
Open this publication in new window or tab >>Water in clinopyroxene from the 2021 Geldingadalir eruption of the Fagradalsfjall Fires, SW-Iceland
Show others...
2023 (English)In: Bulletin of Volcanology, ISSN 0258-8900, E-ISSN 1432-0819, Vol. 85, no 5, article id 31Article in journal (Refereed) Published
Abstract [en]

Water content plays a significant role in magma genesis, ascent rate, and, ultimately, in the style and intensity of volcanic eruptions, due to its control on the density, viscosity and melting behaviour of silicate melts. A reliable method for determining the pre-eruptive magmatic water content is to use phenocrysts of nominally anhydrous minerals (NAMs) which can preserve water as hydrogen configurations in structural defects. The advantage of this method is that eruptive changes such as water loss during magma degassing may be experimentally reconstructed and analysed by infrared spectroscopy. Applying this to clinopyroxene crystals (n=17) from lava samples (n=7) from April 2021 of the Geldingadalir eruption, SW-Iceland, reveals parental water contents of 0.69 ± 0.07 to 0.86 ± 0.09 wt. % H2O. These values are higher than those expected for typical mid-ocean ridge basalts (MORB 0.3–0.5 wt. % on average) indicating a significant plume (OIB) contribution to the magma source. Moreover, such water concentrations would imply that water saturation in the ascending Geldingadalir magmas was attained only at very shallow levels within the plumbing system. This could explain the at times pulsating behaviour within the uppermost conduit system as being the result of shallow episodic water vapour exsolution in addition to the deep-sourced CO2 flux.

Place, publisher, year, edition, pages
Springer, 2023
Keywords
Water in nominally anhydrous minerals, Clinopyroxene phenocrystals, Pulsating eruption, Shallow magma degassing, Geldingadalir
National Category
Geology Geosciences, Multidisciplinary Geophysics
Identifiers
urn:nbn:se:uu:diva-521836 (URN)10.1007/s00445-023-01641-4 (DOI)001136367200001 ()
Funder
Swedish Research Council, 2018-05102Swedish Research Council, 2020-03789Swedish Research Council, 2018-04933
Available from: 2024-01-29 Created: 2024-01-29 Last updated: 2024-01-29Bibliographically approved
Weis, F., Troll, V. R., Jonsson, E., Högdahl, K., Harris, C., Sun, W., . . . Dahrén, B. (2022). Absence of hydrothermal oxygen isotope variations in host rocks supports magmatic origin of the giant Grängesberg iron oxide–apatite (IOA) deposit, Central Sweden. International journal of earth sciences, 111(2), 425-437
Open this publication in new window or tab >>Absence of hydrothermal oxygen isotope variations in host rocks supports magmatic origin of the giant Grängesberg iron oxide–apatite (IOA) deposit, Central Sweden
Show others...
2022 (English)In: International journal of earth sciences, ISSN 1437-3254, E-ISSN 1437-3262, Vol. 111, no 2, p. 425-437Article in journal (Refereed) Published
Abstract [en]

The origin of Kiruna-type iron oxide–apatite ores is controversial, and debate presently centres on a ‘magmatic’ versus a ‘hydrothermal’ mode of formation. To complement recent investigations on the Grängesberg iron oxide–apatite ore deposit in the northwestern part of the Palaeoproterozoic Bergslagen ore province in central Sweden, we investigated the oxygen isotope composition of the host rocks of this large iron oxide–apatite ore body. As the metavolcanic and metagranitoid country rocks around the Grängesberg ore body either pre-date or are coeval with ore formation, they would be expected to record an extensive isotopic imprint if the ore body had formed by large-scale hydrothermal processes involving an externally sourced fluid. A direct magmatic formation process, in turn, would have produced localized alteration only, concentrated on the immediate vicinity of the ore body. Here, we test these two hypotheses by assessing the oxygen isotope variations in the host rocks around the main Grängesberg iron oxide–apatite ore body. We analysed oxygen isotopes in quartz from metavolcanic (n = 17) and metagranitoid host rocks (n = 14) from the vicinity of the ore body, and up to 2 km distance along and across the strike of the ore body. Remarkably, we find no significant variation in δ18O values with distance from the ore body, or any deviations in country rock δ18O from common magmatic and/or regional values. Only two samples show shifts to values more negative than the common magmatic range, indicating highly localized hydrothermal overprint only. As a large-scale, low-temperature hydrothermal origin of the ore body through voluminous fluid percolation would be expected to have left a distinct imprint on the oxygen isotope values of the country rocks, our results are more consistent with an ortho-magmatic origin for the Grängesberg iron oxide–apatite ore.

Place, publisher, year, edition, pages
Springer Nature, 2022
Keywords
geology, ore geology, stable isotopes
National Category
Geology
Research subject
Earth Science with specialization in Mineral Chemistry, Petrology and Tectonics
Identifiers
urn:nbn:se:uu:diva-458884 (URN)10.1007/s00531-021-02122-9 (DOI)000718106500001 ()
Available from: 2021-11-17 Created: 2021-11-17 Last updated: 2023-10-31Bibliographically approved
Bindeman, I. N., Deegan, F., Troll, V. R., Thordarson, T., Höskuldsson, Á., Moreland, W. M., . . . Walter, T. R. (2022). Diverse mantle components with invariant oxygen isotopes in the 2021 Fagradalsfjall eruption, Iceland. Nature Communications, 13(1), Article ID 3737.
Open this publication in new window or tab >>Diverse mantle components with invariant oxygen isotopes in the 2021 Fagradalsfjall eruption, Iceland
Show others...
2022 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 13, no 1, article id 3737Article in journal (Refereed) Published
Abstract [en]

The basalts of the 2021 Fagradalsfjall eruption were the first erupted on the Reykjanes Peninsula in 781 years and offer a unique opportunity to determine the composition of the mantle underlying Iceland, in particular its oxygen isotope composition (δ18O values). The basalts show compositional variations in Zr/Y, Nb/Zr and Nb/Y values that span roughly half of the previously described range for Icelandic basaltic magmas and signal involvement of Icelandic plume (OIB) and Enriched Mid-Ocean Ridge Basalt (EMORB) in magma genesis. Here we show that Fagradalsfjall δ18O values are invariable (mean δ18O = 5.4 ± 0.3‰ 2 SD, N = 47) and indistinguishable from “normal” upper mantle, in contrast to significantly lower δ18O values reported for erupted materials elsewhere in Iceland (e.g., the 2014–2015 eruption at Holuhraun, Central Iceland). Thus, despite differing trace element characteristics, the melts that supplied the Fagradalsfjall eruption show no evidence for 18O-depleted mantle or interaction with low-δ18O crust and may therefore represent a useful mantle reference value in this part of the Icelandic plume system.

Place, publisher, year, edition, pages
Nature, 2022
National Category
Geochemistry
Identifiers
urn:nbn:se:uu:diva-482020 (URN)10.1038/s41467-022-31348-7 (DOI)000830675000026 ()35768436 (PubMedID)
Funder
Swedish Research Council, 2018-04933Swedish Research Council, 2016-04838
Available from: 2022-08-18 Created: 2022-08-18 Last updated: 2023-03-28Bibliographically approved
Darmawan, H., Troll, V. R., Walter, T. R., Deegan, F., Geiger, H., Heap, M. J., . . . Müller, D. (2022). Hidden mechanical weaknesses within lava domes provided by buried high-porosity hydrothermal alteration zones. Scientific Reports, 12, Article ID 3202.
Open this publication in new window or tab >>Hidden mechanical weaknesses within lava domes provided by buried high-porosity hydrothermal alteration zones
Show others...
2022 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, article id 3202Article in journal (Refereed) Published
Abstract [en]

Catastrophic lava dome collapse is considered an unpredictable volcanic hazard because the physical properties, stress conditions, and internal structure of lava domes are not well understood and can change rapidly through time. To explain the locations of dome instabilities at Merapi volcano, Indonesia, we combined geochemical and mineralogical analyses, rock physical property measurements, drone-based photogrammetry, and geoinformatics. We show that a horseshoe-shaped alteration zone that formed in 2014 was subsequently buried by renewed lava extrusion in 2018. Drone data, as well as geomechanical, mineralogical, and oxygen isotope data suggest that this zone is characterized by high-porosity hydrothermally altered materials that are mechanically weak. We additionally show that the new lava dome is currently collapsing along this now-hidden weak alteration zone, highlighting that a detailed understanding of dome architecture, made possible using the monitoring techniques employed here, is essential for assessing hazards associated with dome and edifice failure at volcanoes worldwide.

Place, publisher, year, edition, pages
Springer NatureSpringer Nature, 2022
National Category
Geology
Identifiers
urn:nbn:se:uu:diva-470553 (URN)10.1038/s41598-022-06765-9 (DOI)000761274300020 ()35217684 (PubMedID)
Available from: 2022-03-28 Created: 2022-03-28 Last updated: 2024-01-15Bibliographically approved
Sahlström, F., Troll, V. R., Palinkas, S. S., Kooijman, E. & Zheng, X.-Y. (2022). Iron isotopes constrain sub-seafloor hydrothermal processes at the Trans-Atlantic Geotraverse (TAG) active sulfide mound. Communications Earth & Environment, 3, Article ID 193.
Open this publication in new window or tab >>Iron isotopes constrain sub-seafloor hydrothermal processes at the Trans-Atlantic Geotraverse (TAG) active sulfide mound
Show others...
2022 (English)In: Communications Earth & Environment, E-ISSN 2662-4435, Vol. 3, article id 193Article in journal (Refereed) Published
Abstract [en]

Iron isotopic equilibration at the Trans-Atlantic Geotraverse hydrothermal field takes place over tens of thousands of years, with variable degrees of hydrothermal maturation throughout the active mound, according to iron isotope analyses of sulfide minerals. Sub-seafloor hydrothermal processes along volcanically active plate boundaries are integral to the formation of seafloor massive sulfide deposits and to oceanic iron cycling, yet the nature of their relationship is poorly understood. Here we apply iron isotope analysis to sulfide minerals from the Trans-Atlantic Geotraverse (TAG) mound and underlying stockwork, 26 degrees N Mid-Atlantic Ridge, to trace hydrothermal processes inside an actively-forming sulfide deposit in a sediment-free mid-ocean ridge setting. We show that data for recently formed chalcopyrite imply hydrothermal fluid-mound interactions cause small negative shifts (<-0.1 parts per thousand) to the delta Fe-56 signature of dissolved iron released from TAG into the North Atlantic Ocean. Texturally distinct types of pyrite, in turn, preserve a delta Fe-56 range from -1.27 to +0.56 parts per thousand that reflects contrasting precipitation mechanisms (hydrothermal fluid-seawater mixing vs. conductive cooling) and variable degrees of progressive hydrothermal maturation during the >20 kyr evolution of the TAG complex. The identified processes may explain iron isotope variations found in fossil onshore sulfide deposits.

Place, publisher, year, edition, pages
Springer Nature, 2022
National Category
Oceanography, Hydrology and Water Resources Geology
Identifiers
urn:nbn:se:uu:diva-484212 (URN)10.1038/s43247-022-00518-2 (DOI)000847349500001 ()
Funder
Swedish Research Council, 2020-03789
Available from: 2022-09-09 Created: 2022-09-09 Last updated: 2022-09-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1891-3396

Search in DiVA

Show all publications