Sökning: "subduktion"

Visar resultat 1 - 5 av 8 uppsatser innehållade ordet subduktion.

  1. 1. Magmatic Sources and Processes Recorded by the Volcanics from the Izu Bonin Rear Arc

    Master-uppsats, Uppsala universitet/Institutionen för geovetenskaper

    Författare :John Owen Edgar; [2017]
    Nyckelord :Izu-Bonin; plagioclase; magma; strontium; thermobarometry; rear arc; Izu-Bonin; plagioklas; magma; strontium; termobarometri; bakbåge;

    Sammanfattning : The Izu rear-arc volcanism was investigated by IODP EXP350 in spring 2014. A total stratigraphy of1800 m was drilled, and contains volcaniclastic material within tuffaceous mudstone. LÄS MER

  3. 2. Behaviour of Boron Isotopes During Magmatic Degassing and Application to B-Rich Volcanic Glassfrom Lesbos, Greece

    Master-uppsats, Uppsala universitet/Institutionen för geovetenskaper

    Författare :Konstantinos Thomaidis; [2017]
    Nyckelord :boron isotopes; volcanic glass; SIMS; magmatic degassing; Lesbos Island; borisotoper; vulkaniskt glas; SIMS; magmatisk avgasning; Lesbos;

    Sammanfattning : Boron is a fluid mobile trace element and is routinely employed as a tracer of slab-derived fluids in subduction zones since the heavy isotope (11B) preferentially partitions into the fluid phase during slab dehydration. However, it has been shown experimentally that boron isotopes (expressed as δ11B) can fractionate by up to several permil (‰) during subsequent magmatic evolution and degassing at high temperature, calling into doubt the fidelity of boron isotopes in volcanic glass as accurate tracers of slab degassing. LÄS MER

  4. 3. Mantelplymer : realitet eller ad hoc?

    Kandidat-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Alfred Larsson; [2015]
    Nyckelord :uppsmältning; seismik; hotspot; litosfär; mantelplym; Earth and Environmental Sciences;

    Sammanfattning : Mantle plumes are subject of a great discussion within the field of Geology. Do they really exist, and in that case, from where do they originate? The scope of this Bachelor thesis is to discuss the characteristics of mantle plumes and the arguments in favor of and against their proposed existence. LÄS MER

  5. 4. Pressure Temperature Conditions of the Otrøy Opmhacite-Garnet Gneiss, Western Gneiss Region, Skandinavian Caledonides

    Kandidat-uppsats, Uppsala universitet/Institutionen för geovetenskaper

    Författare :Johanna Holmberg; [2015]
    Nyckelord :Western Gneiss Region; Otrøy; gneiss; ultrahigh-pressure metamorphism; Western Gneiss Region; Otrøy; gnejs; ultrahögtrycksmetamorfos;

    Sammanfattning : Garnet-omphacite gneisses from the island of Otrøy situated in Western Gneiss Region (WGR), Norway, Scandinavian Caledonides, were examined within this study. The WGR is one of the planets most studied ultrahigh-pressure (UHP) terranes. The studied gneisses are hosts for UHP garnet peridotites and eclogites. LÄS MER

  7. 5. Hur bildades Bushveldkomplexet?

    Kandidat-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Filip Ivarsson; [2015]
    Nyckelord :chromite; intrusion; platinum; LIP; Bushveld Complex; Earth and Environmental Sciences;

    Sammanfattning : The Bushveld complex is the world’s largest mafic intrusion and located on the Archean Kaapvaal craton, southern Africa. The complex’s host rock has anomalous quantities of platinum-group elements (PGE), chromite and other valuable metals of high demand. LÄS MER