Sökning: "Olivine alteration"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Olivine alteration.

1. 1. Low temperature olivine alteration ; an experimental approach

   Författare :Anna Neubeck; Nils Holm; Gretchen Früh-Green; Stockholms universitet; []
   Nyckelord :Olivine alteration; hydrogen; methane; serpentinization; geokemi; Geochemistry;

   Sammanfattning : Water reacting with minerals to alter or dissolve them is a common phenomenon on Earth, leading to a unique chemical composition of the oceans and continents. The continuous circulation of elements and the chemical reactions between them creates the extraordinary environment prevailing on our Earth today and was probably an important requirement for the onset of life on our planet. LÄS MER

3. 2. Origin and composition of the Hällefors composite dyke, central Sweden

   Författare :Ricardo Lopez-Montano; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The Hällefors dyke is a large, wedge-shaped high-level intrusion that trends E-W and has a subvertical dip, the overall dimensions being about 42 km in length and 1 km in width. It was emplaced ca 1550 Ma ago in gneisses of the Svecokarelian (1950-1750 Ma) orogenic belt in south central Sweden. LÄS MER

4. 3. Crystallization and Differentiation Processes in the Thin Layered Alkali Gabbroic Intrusions of the Ulvö Gabbro Complex, Central Sweden

   Författare :Johan Hogmalm; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; layered intrusion; fractional crystallization; modal layering; in situ crystallization; Ulvö; saucer-shaped sill; post-cumulus; LA ICP-MS;

   Sammanfattning : Fractional crystallization of magma is a commonly invoked mechanism for chemical differentiation in systems that range from volcanoes to entire planets. However, the processes that control separation of crystals and liquids in natural systems remain controversial, since the dynamics of crystallizing magma chambers cannot be studied directly. LÄS MER

5. 4. Petrology and Geochemistry of the nakhlite meteorites : Tracking complex igneous and aqueous processes on Mars during the Amazonian

   Författare :Hélène Breton; University of Glasgow; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mars; Nakhlites; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : The overarching science question being addressed by this research project was the geological history of the nakhlite group of Martian meteorites as representative of a young Amazonian Martian crust. This included the magmatic processes and mechanism of emplacement at the origin of the meteorites but also the nature of a young Amazonian Martian aquifer that circulated throughout the nakhlites bedrock from its chemistry, origin and longevity. LÄS MER

7. 5. The geochemistry and petrogenesis of the Notträsk mafic intrusion, northern Sweden

   Författare :Nikos Arvanitidis; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The Notträsk intrusive body is an early Proterozoic layered mafic intrusion probably of lopolithic form. It intrudes metasedimentary gneisses and shows the characteristics of Precambrian plutons which are contemporaneous with intercratonic tholeiitic volcanism; it represents the cumulates of a crustal-level magma chamber that may have been the source of basaltic volcanism in the area. LÄS MER