UCM-EEA Abel Extraordinary Chair. Coordinated Mobility of Researchers. NILS Science and Sustainability (ES07)

“FLOWS AND BLOWS OF THE ICELANDIC PAST: APPLICATION OF ROCK MAGNETISM TO UNRAVEL TRANSPORT DYNAMICS OF NEOGENE VOLCANIC ERUPTIONS IN EASTERN ICELAND”

(004-ABEL-CM-2014A)

(June 2014 - December 2015)



Coordinators at project promoter / partner institution:

VICENTE CARLOS RUIZ MARTÍNEZ & MORTEN RIISHUUS SCHIOLDAN

(Universidad Complutense de Madrid, Spain / Institute of Earth Sciences, University of Iceland, Iceland)

 

Supported by a grant from Iceland, Liechtenstein and Norway through the EEA Financial Mechanism.

Operated by Universidad Complutense de Madrid.

www.nilsmobilityproject.es

Summary

Exceptionally well preserved volcanic units and groups in eastern Iceland provide an ideal opportunity for interdisciplinary studies attempting to achieve a deeper understanding of the surface dynamics of volcanic processes at oceanic spreading ridges. Magnetic particles of such igneous rocks are exceptional recorders not only of the ancient geomagnetic field but also of fossil flow directions of dykes, lava flows and welded tuffs. Paleomagnetic and anisotropy of magnetic susceptibility (rock fabric) studies will be applied to determine flow direction and vent sources for specific volcanic deposits where structural field evidence is available. The project is planned in sequential steps: (i) Fieldwork in eastern Iceland to collect oriented drill cores from volcanic rocks, (ii) laboratory treatment and statistical analysis in Madrid, and (iii) revisit Iceland for resampling/ collaboration on interpretations of results. It will add to our understanding of Icelandic fossil explosive volcanic processes and tectono-magmatic evolution. Characterization of ancient eruption processes aims to add a better understanding of active volcanic systems.

Why the Project was needed:

The anisotropy of the magnetic susceptibility (AMS) is a relatively fast method to measure rock fabrics. In addition to field observations and rock textures, AMS studies have proven useful to determine intrusive and eruptive transport and depositional processes. The past 15 years have seen a marked expansion in the application of AMS to volcanic processes. Recent volcanic events in Iceland (2010 Eyjafjallajökull and 2014-15 Bardarbunga eruptions) have impacted on the public awareness toward the need for advancement of our knowledge on many aspects of volcanic hazards. The project seeks to contribute to this by attempting to relate rock fabrics of pyroclastic density currents and lava flows in the Neogene archives of eastern Iceland to eruptive transport and depositional processes.

Workplan carried out:

Due to the 2014-15 Bardarbunga volcanic crisis the effectuated work plan has deviated significantly from the original planned work plan. According to the original plan Vicente Carlos Ruiz Martínez (VCRM) would visit Morten Schioldan Riishuus (MSR) in Iceland during summer/early autumn of 2014 for a joint field campaign. However, due to the 6-months long eruption that started in late August 2014 (and the preceding volcanic unrest) that required the full-time participation of MSR in ground monitoring (and caused the fieldwork to be unpredictable or an unhealthy risk), the decision to postpone the field campaign by one year was made. This has negatively affected the progress of the project and the ability of the co-directors (co-PIs) to hold the planned expenses within a non-negotiable fixed deadline for final reporting of the mobility transfers and research. It also has caused the transferring of funds (<15%) from stays to travels, and the returning of 1320.26 euros (20% of the assigned funds were not used):

VCRM visited MSR in Iceland in the period July 16-30, 2015, during which fieldwork was conducted in eastern Iceland, using the MSR personal vehicle. It is noteworthy that, unfortunately, none of the MSR costs during his (Icelandic) fieldwork could be funded by the project -neither gasoline nor others-, and all them were personally assumed by both co-PIs (approximately the same amount of money which was unused at the end of the project).

MSR made two stays at Universidad Complutense de Madrid with VCRM (October 19-25 and November 1-6, 2015) during which planned measurements of anisotropy of magnetic susceptibility and hysteresis were performed at the UCM paleomagnetism laboratory. The two mobility transfers held by MSR also deviates from the original plan of one mobility transfer by each of the co-PIs after the fieldwork had ended. Since data collection took place in October-November 2015 (during September, oriented samples were cut in standard-volume specimens for AMS measurements, and remaining rock-chips were classified for rock-magnetic experiments), there was no incentive for VCRM to visit MSR at the University of Iceland at this early stage of the research. Since all the analytical work is to be carried out at UCM, the decision was made for MSR to complete two transfers at UCM during autumn 2015 to participate in the data acquisition.

During the mobility transfers to UCM, relevant theoretical and applied research papers relevant to the research were discussed as well as the preliminary data being collected. Interaction with UCM-based research groups and students was also made.

Scientific activity and results obtained during the project implementation:

Fieldwork (Eastern Iceland): A total of 213 cores were drilled, individually oriented, and retrieved from 24 sites, including sites from all targeted geological units: Skessa and Bjólfur tuffs (6 sites); Holmar and Grjótá olivine basalt groups (7 sites); Kumlafell aphyric basalt group (5 sites). In addition, lava flows (3 sites), dikes (2 sites) and a redbed sedimentary unit between flows (1 site) were also sampled.