Sökning: "magmatism"

Visar resultat 1 - 5 av 32 avhandlingar innehållade ordet magmatism.

  1. 1. New Zircon geochronological and Nd isotopic evidence for Neoproterozoic crust reworking events in the Abas terrane, Yemen

    Författare :Fitsum Girum Yeshanew; Victoria Pease; Martin Whitehouse; Hugh Rollinson; Kjell Billström; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Precambrian; Arabian Shield; magmatism; U-Pb; zircon; post-collisional magmatism; Nd isotopes; Geology; geologi;

    Sammanfattning : The Arabian-Nubian Shield is an excellent natural laboratory to study crust formation processes during the Neoproterozoic. It is one of the largest juvenile tracts of continental crust formed during this time. It diachronously evolved between the breakup of Rodinia (c.780 Ma) and amalgamation of Gondwana (c. LÄS MER

  3. 2. Magmatism in the Cenozoic Ethiopian rift zone : the case against the Afar plume hypothesis

    Författare :Begashaw Wolde; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

    Sammanfattning : Volcanism and rifting in the Afro-Arabian, i.e. Red Sea - Gulf of Aden - Ethiopian, region have often been attributed to a Tertiary plume centered on Afar, at the junction of the three rifts. LÄS MER

  4. 3. Silicic Magma Genesis in Basalt-dominated Oceanic Settings : Examples from Iceland and the Canary Islands

    Författare :Sylvia E. Berg; Valentin Troll; Steffi Burchardt; Frances Deegan; Morten Riishuus; Nicholas Arndt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Silicic magmatism; Iceland; magma-crust interaction; proto-continental crust; early Earth; zircon geochronology and geochemistry; oxygen isotopes; 2011-2012 El Hierro eruption; crustal xenoliths; 3D X-ray μ-CT; volatiles; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : The origin of silicic magma in basalt-dominated oceanic settings is fundamental to our understanding of magmatic processes and formation of the earliest continental crust. Particularly significant is magma-crust interaction that can modify the composition of magma and the dynamics of volcanism. LÄS MER

  5. 4. Processes of Magma-crust Interaction : Insights from Geochemistry and Experimental Petrology

    Författare :Frances M Deegan; Valentin R Troll; Luigi Dallai; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Canary Island magmatism; HP-HT experimental petrology; magma-crust interaction; Merapi volcano; radiogenic isotopes Sr; Nd; Pb ; stable isotopes O; B .; Solid earth geology and petrology; Berggrundsgeologi och petrologi; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : This work focuses on crustal interaction in magmatic systems, drawing on experimental petrology and elemental and isotope geochemistry. Various magma-chamber processes such as magma-mixing, fractional crystallisation and magma-crust interaction are explored throughout the papers comprising the thesis. LÄS MER

  7. 5. Tectonic implications of ca. 1.45 Ga granitoid magmatism at the southwestern margin of the East European Craton

    Författare :Audrius Cecys; Berggrundsgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geologi; southern Sweden; fysisk geografi; physical geography; Mesoproterozoic; geochemistry; syntectonic; petrology; structural geology; anisotropy of magnetic susceptibility; Danopolonian orogeny; Geology; granite;

    Sammanfattning : Between ca 1.53 and 1.40 Ga, the southwestern margin of the East European Craton was subjected to extensive magmatism and deformation. While various suites of anorthositic, mangeritic and charnockitic-granitic rocks were emplaced between ca. LÄS MER