Sökning: "Continental crust"

Visar resultat 1 - 5 av 30 avhandlingar innehållade orden Continental crust.

  1. 1. Magma generation and formation of continental crust in the Izu arc

    Författare :Haochen Duan; Abigail Barker; Jaroslaw Majka; Stefan Wastegård; Kate Saunders; Susanne M. Straub; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Oceanic arc; Izu rear-arc; Melt inlcusions; Oxygen isotopes; Boron isotopes; Continental crust; Mantle hererogeneity; In-situ microanalysis; IMS-1280; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : The Izu oceanic arc is produced by the subduction of the Pacific Sea Plate beneath the Philippine Sea Plate. The proto-Izu oceanic arc was initially formed at ca. 50 Ma, then it was separated into the Kyushu-Palau and Izu arc by the extension of the Shikoku basin from ca. 25 Ma. LÄS MER

  3. 2. Chemical and isotopic records of polycyclic histories in a subducted continental crust (Dora-Maira Massif, Western Alps)

    Författare :Francesco Nosenzo; Paola Manzotti; Alasdair Skelton; Charlotte Möller; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Subduction; continental crust; polycyclic; garnet; metamorphic petrology; Geology; geologi;

    Sammanfattning : At convergent plate margin, part of the continental crust can be subducted and exhumed. During continental subduction a pre-existing crust is reworked. Remnants of an older orogen are recycled and subjected to (ultra)-high-pressure metamorphism. LÄS MER

  4. 3. Electromagnetic studies of the continental crust in Sweden

    Författare :Mehran Gharibi; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : Plane-wave electromagnetic methods are powerful tools for probing the earth from the surfaceto depths of a few hundred kilometers. The airborne VLF technique is widely used to map theelectrical conductivity variations of shallow geological structures. LÄS MER

  5. 4. 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

  7. 5. Seismic imaging of deep crustal reflectivity in Sweden and Iceland

    Författare :Niklas Juhojuntti; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; seismic; reflectivity; Moho; crust; signal; Geofysik; Geophysics; Geofysik; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

    Sammanfattning : Seismic reflection profiling, originally developed by the petroleum industry, was adapted to systematic imaging of deep structures some 25 years ago. In continental areas, these measurements often show weakly reflective upper crust and strongly reflective lower crust. LÄS MER