dc.contributor |
Háskóli Íslands |
dc.contributor |
University of Iceland |
dc.contributor.author |
Kleine, Barbara Irene |
dc.contributor.author |
Stefansson, Andri |
dc.contributor.author |
Kjartansdóttir, Ríkey |
dc.contributor.author |
Prause, Simon |
dc.contributor.author |
Weisenberger, Tobias B. |
dc.contributor.author |
Reynolds, Hannah Iona |
dc.contributor.author |
Sveinbjörnsdóttir, Árný |
dc.contributor.author |
Jackson, Marie D. |
dc.contributor.author |
Gudmundsson, Magnus Tumi |
dc.date.accessioned |
2020-12-01T13:13:21Z |
dc.date.available |
2020-12-01T13:13:21Z |
dc.date.issued |
2020-09 |
dc.identifier.citation |
Kleine, B. I., Stefánsson, A., Kjartansdóttir, R., Prause, S., Weisenberger, T. B., Reynolds, H. I., . . . Gudmundsson, M. T. (2020). The Surtsey volcano geothermal system: An analogue for seawater-oceanic crust interaction with implications for the elemental budget of the oceanic crust. Chemical Geology, 550, 119702. doi:https://doi.org/10.1016/j.chemgeo.2020.119702 |
dc.identifier.issn |
0009-2541 |
dc.identifier.uri |
https://hdl.handle.net/20.500.11815/2264 |
dc.description |
Pre-print (óritrýnt handrit) |
dc.description.abstract |
Surtsey is a young volcanic island in the offshore extension of Iceland's southeast rift zone that grew from the seafloor during explosive and effusive eruptions in 1963–1967. In 1979, a cored borehole (SE-1) was drilled to 181 m depth and in 2017 three cored boreholes (SE-2a, SE-2b and SE-3) were drilled to successively greater depths. The basaltic deposits host a low-temperature (40–141 °C) seawater-dominated geothermal system.
Surtsey provides an ideal environment to study water-rock interaction processes in a young seawater geothermal system. Elemental concentrations (SiO2, B, Na, Ca, Mg, F, dissolved inorganic carbon, SO4, Cl) and isotope contents (δD, δ18O) in borehole fluids indicate that associated geothermal waters in submarine deposits originated from seawater modified by reactions with the surrounding basalt. These processes produce authigenic minerals in the basaltic lapilli tuff and a corresponding depletion of certain elements in the residual waters. Coupling of measured and modelled concentrations investigates the effect of temperature and associated abundance of authigenic minerals on chemical fluxes from and to the igneous oceanic crust during low-temperature alteration. The annual chemical fluxes calculated at 50–150 °C range from −0.01 to +0.1×1012 mol yr−1 for SiO2, +0.2 to +129×1012 mol yr−1 for Ca, −129 to −0.8×1012 mol yr−1 for Mg and −21 to +0.4 × 1012 mol yr−1 for SO4 where negative values indicate chemical fluxes from the ocean into the oceanic crust and positive values indicate fluxes from the oceanic crust to the oceans. These flux calculations reveal that water-rock interaction at varying water-rock ratios and temperatures produces authigenic minerals
that serve as important sinks of seawater-derived SiO2, Mg and SO4. In contrast, water rock interaction accompanied by dissolution of basaltic glass and primary crystal fragments provides a significant source of Ca. Such low-temperature alteration could effectively influence the elemental budget of the oceanic igneous crust and ocean waters. The modeling provides insights into water chemistries and chemical fluxes in low temperature MOR recharge zones. Surtsey also provides a valuable young analogue for assessing the chemical evolution of fluid discharge over the life cycles of seamounts in ridge flank systems. |
dc.description.sponsorship |
Funding for this project was provided by the University of Iceland Recruitment fund, the International Continental Scientific Drilling Program (ICDP) through a grant to the SUSTAIN project, the Icelandic Science Fund, ICF-RANNÍS, the Bergen Research Foundation and K.G. Jebsen Centre for Deep Sea Research at University of Bergen, Norway, the German Research Foundation (DFG), and DiSTAR, Federico II, University of Naples, Federico II, Italy. The University of Utah, USA and the two Icelandic power companies Reykjavík Energy and Landsvirkjun, contributed additional funds. The authors would like to thank P. Bergsten, A.M. di Stefano, C.F. Gorny, J. Gunnarsson-Robin, G.H. Guðfinsson, Þ. Högnadóttir, E.W. Marshall, R. Ólafssdóttir, D.B. Ragnarsson and Þ.M. Þorbjarnardóttir for their contribution and assistance during sampling, sample preparation, analyses and data evaluation. The authors would like to thank M. E. Böttcher for careful editorial handling. Two anonymous reviewers and J. Alt are thanked for their thoughtful and valuable reviews. |
dc.format.extent |
119702 |
dc.language.iso |
en |
dc.publisher |
Elsevier BV |
dc.relation.ispartofseries |
Chemical Geology;550 |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.subject |
Surtsey volcano |
dc.subject |
Oceanic crust |
dc.subject |
Water-rock interaction |
dc.subject |
ICDP |
dc.subject |
Surtseyjargosið |
dc.subject |
Eldfjöll |
dc.subject |
Basalt |
dc.title |
The Surtsey volcano geothermal system: An analogue for seawater-oceanic crust interaction with implications for the elemental budget of the oceanic crust |
dc.type |
info:eu-repo/semantics/article |
dc.identifier.journal |
Chemical Geology |
dc.identifier.doi |
10.1016/j.chemgeo.2020.119702 |
dc.contributor.department |
Jarðvísindastofnun (HÍ) |
dc.contributor.department |
Institute of Earth Sciences (UI) |
dc.contributor.school |
Verkfræði- og náttúruvísindasvið (HÍ) |
dc.contributor.school |
School of Engineering and Natural Sciences (UI) |