Sökning: "upper mantle"

Visar resultat 16 - 19 av 19 avhandlingar innehållade orden upper mantle.

  1. 16. GPS for Geophysics: Glacial Isostatic Adjustment and Tests of Ionospheric Models

    Författare :Sten Bergstrand; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; rheology; noise; crustal deformation; horizontal movement; time series analysis; ionosphere; GPS; NeQuick;

    Sammanfattning : This dissertation is divided into two parts that separately utilize high precision Global Positioning System (GPS) satellite observations for inferences of solid earth and ionospheric parameters.In the first part of the dissertation, solid earth movements in Sweden and Finland are observed with GPS at a precision of the order 0.1 mm/yr. LÄS MER

  3. 17. Magma-Crust Interaction at Subduction Zone Volcanoes

    Författare :Ester M. Jolis; Valentin R Troll; Silvio Mollo; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; magma-crust interaction; stable isotopes O-C ; radiogenic isotopes Sr-Nd-Pb ; calc-silicate xenoliths; HP-HT experimental petrology; crustal volatiles; Vesuvius; Merapi; Kelut; the Sunda arc; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : The focus of this work is magma-crust interaction processes and associated crustal volatile release in subduction zone volcanoes, drawing on rock, mineral, and gas geochemistry as well as experimental petrology. Understanding the multitude of differentiation processes that modify an original magma during ascent to the surface is vital to unravel the contributions of the various sources that contribute to the final magmas erupted at volcanoes. LÄS MER

  4. 18. Geophysical vectoring of mineralized systems in northern Norrbotten

    Författare :Roshanak Vadoodi; Thorkild Maack Rasmussen; Maxim Smirnov; Behrooz Oskooi; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetotelluric; Electrical Conductivity; Potential Field; 3D Inversion; Mineralisation; Classification; Self-Organizing Map SOM ; Exploration Geophysics; Prospekteringsgeofysik;

    Sammanfattning : The Fennoscandian Shield as a part of a large Precambrian basement area is located in northern Europe and hosts economically important mineral deposits including base metals and precious metals. Regional geophysical data such as potential field and magnetotelluric data in combination with other geoscientific data contain information of importance for an understanding of the crustal and upper mantle structure. LÄS MER

  5. 19. Integrated analyses and interpretations of regional scale magnetotelluric and potential field data from the Precambrian crust of northern Sweden

    Författare :Roshanak Vadoodi; Thorkild Maack Rasmussen; Maxim Smirnov; Björn H. Heincke; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Exploration Geophysics; Prospekteringsgeofysik;

    Sammanfattning : The Norrbotten region in northern Sweden, as a part of the Fennoscandian (Baltic) Shield, is one of the most active mining areas in Europe. It is acknowledged that geological structures such as faults, shear zones, and associated fracture systems play a key role in providing a physical pathway connecting metal sources and the sites of mineral precipitation. LÄS MER