Sökning: "ultramafic"

Visar resultat 1 - 5 av 10 avhandlingar innehållade ordet ultramafic.

  1. 1. Origin of organic compounds in fluids from ultramafic-hosted hydrothermal vents of the Mid-Atlantic Ridge

    Författare :Cécile Konn; Nils Holm; Jean-Luc Charlou; Barbara Sherwood Lollar; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Serpentinisation; hydrocarbons; organic compounds; ultramafic; hydrothermal; geochemistry; origin of life; Other earth sciences; Övrig geovetenskap; Other chemistry; Övrig kemi; Exogenous geochemistry; Exogen geokemi; geokemi; Geochemistry;

    Sammanfattning : Natural gas, primarily methane (CH4), is produced in substantial amounts in ultramafic-hosted hydrothermal systems. These systems could also generate oil (heavier hydrocarbons) and the first building blocks of life (prebiotic molecules). In the presence of iron bearing minerals, serpentinisation reactions generate H2. LÄS MER

  3. 2. Diversification on an ancient Darwinian island : Evolutionary history of caddisflies (Trichoptera) and other organisms on New Caledonia

    Författare :Marianne Espeland; Kjell Arne Johanson; Niklas Wahlberg; Michael Balke; Stockholms universitet; []
    Nyckelord :New Caledonia; Trichoptera; island; biogeography; phylogenetics; DNA; dispersal; vicariance; adaptation; ultramafic; diversification; new species; environmental factors; Systematic Zoology; zoologisk systematik och evolutionsforskning;

    Sammanfattning : Islands are either of continental or oceanic origin, and the biota of such islands are a result of vicariance and dispersal, respectively. New Caledonia, in the South Pacific, is a part of former Gondwana, but the origin of its biota is heavily debated. LÄS MER

  4. 3. Nickel partitioning in olivine and its decomposition products in serpentinized ultramafic rocks

    Författare :Anestis Filippidis; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  5. 4. Organics in hydrothermal fluids from ultramafic-hosted vents of the Mid-Atlantic Ridge

    Författare :cecile konn; Stockholms universitet; []
    Nyckelord :hydrothermal; organics; serpentinization; origin of life;

    Sammanfattning : The process of serpentinization at slow spreading ridges is due to the circulation of seawater through outcropping mantle rocks. The peridotites of the mantle are altered via fluid-rock interaction generating, in the presence of Fe bearing minerals, high CH4- and H2-concentrations in the water column. LÄS MER

  7. 5. Geochemical and geochronological constraints on 1.88 and 1.80 Ga magmatic events in the Gällivare area, northern Sweden

    Författare :Zimer Sarlus; Paul Evins; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

    Sammanfattning : The Gällivare area is situated in northern Norrbotten, Sweden, and hosts the Aitik Cu-Au deposit and the Malmberget Fe deposit. In addition, more than 17 mineral prospects and mineralizations are present, among these the currently developed Nautanen Cu-Au deposit. LÄS MER