Igneous petrology & geochemistry
We investigate mantle source heterogeneity and lithologies of materials recycled into the mantle at subduction zones, subduction zone processes and geochemical fluxes. Another focus is magma storage to constrain pre-eruptive magmatic processes and crystallisation conditions, in collaboration with volcanology and volcano monitoring this work contributes to volcanic hazard research. We employ a wide range of petrological and geochemical techniques including major and trace element and isotope geochemistry on bulk rock as well as minerals. Research involves tholeiitic, calc-alkaline, alkaline and carbonatitic rocks from a variety of volcanic settings including Ocean islands, volcanic arcs, Large Igneous Provinces. Additionally, we conduct research on igneous rocks of continental crustal and orogenic terrains of Scandinavia and the Arctic. There are strong links and collaboration with the metamorphic petrology group (see below).
Our research is focused on understanding the course and dynamics of metamorphic processes from shallow crust to mantle depths. We aim on deciphering pressure-temperature-time-deformation-fluid histories of metamorphic rock complexes to elucidate evolutionary paths of metamorphic terranes. Of special interest are the rocks formed in orogenic setting, during subduction and collisional processes. Our toolkit includes state-of-the-art imaging, analytical and modelling techniques. We combine conventional geothermobarometry and phase equilibrium modelling together with trace element and elastic thermobarometry. Detailed studies of solid and fluid inclusions accompany pressure-temperature estimates to better understand volatile component recycling and budgets as well as their role in partial melting. A variety of petrochronologic techniques are applied to link metamorphism, deformation and duration and timing of the metamorphic processes. Our research efforts are focused mostly on the Svekofennian, Caledonian, Variscan and Alpine orogens. Additionally, we conduct research on metamorphosed and fluid-reworked ore deposits. We collaborate closely with igneous and ore petrologists within our research division and beyond.
Our research group at Uppsala University studies magmatic processes from the source to surface and from crystal to plate-boundary scale. Our research expertise focuses on igneous and metamorphic petrology and high temperature geochemistry, experimental petrology, physical volcanology, volcano-tectonics, geothermal systems, volcanogenic ores, volcanic gases and the carbon cycle, contact metamorphism of host rock and xenoliths, as well as deep subduction zone processes.
Regarding volcanic eruptions, such as el Hierro 2011/2012 and Bárđabunga 2014, the group has the ability to rapidly perform mineral-scale elemental analyses on small volume samples using the in-house JEOL JXA-8530 Hyperprobe (FEG-EPMA). The resulting mineral chemistry data are employed for thermobarometry calculations to provide robust pressure estimates for various crystallising phases, which can then be converted to depth to trace the magma storage system feeding the eruption. The group has established a track record in application of such methods. Moreover, the group can analyse and interpret fault propagation and magma movement in volcanoes through theoretical and analogue approaches, which can then be linked with thermobarometry calculations to construct an integrated model of magma storage and ascent processes.
The group works in a wide variety of tectonic settings from Ocean Islands, through Subduction zones and their exhumed equivalents to Large Igneous Provinces (LIPs). Research on magma plumbing systems is integrated with investigation of geothermal systems, formation of volcaniogenic ore, contact metamorphism of country rock and assimilation processes, and with gases released from the magma and due to contact metamorphism. Additionally, magma genesis and sources are investigated including the role of slab-derived sources in subduction zones. The study of deep subduction processes encompasses exhumed diamond-bearing ultra-high pressure terrains.
The group’s extensive knowledge and varied expertise is based on i) field experience in some of the best exposed eroded and active volcanoes and exhumed subduction zones worldwide, ii) scaled analogue and numerical modelling of the process of volcano-magmatic and metamorphic processes, iii) routine in-house FEG-EPMA analysis and thermobarometry studies, iv) long-standing experience with analysis and modelling of high-temperature geochemical data, including stable and radiogenic isotopes of solid and gaseous erupted materials, and v) high pressure-temperature experimental simulations of magmatic processes. Our research group therefore possesses a “toolkit” to generate and interpret combined petrological and structural datasets to reconstructing magma plumbing systems and crustal architecture.