Essays about: "tims"

Showing result 1 - 5 of 6 essays containing the word tims.

  1. 1. Rb-Sr sphalerite data and implications for the source and timing of Pb-Zn deposits at the Caledonian margin in Sweden

    University essay from Lunds universitet/Geologiska institutionen

    Author : Alfred Larsson; [2018]
    Keywords : Laisvall; Granberget; geochronology; sphalerite; ore; Rb-Sr; Earth and Environmental Sciences;

    Abstract : The eastern Caledonian erosional front hosts the world-class Pb-Zn deposit at Laisvall (64 Mt mined) and Granberget mineralization, northern Sweden, along with several other smaller, related types of deposits consisting of impregnation mineralization of galena and sphalerite in clastic host rocks. Previous work have discussed the nature of the ore-forming processes and constraints for the timing of the mineralization, however, the mechanisms are still not fully understood and previous age determinations are ambiguous. READ MORE

  2. 2. Magmatic Sources and Processes Recorded by the Volcanics from the Izu Bonin Rear Arc

    University essay from Uppsala universitet/Institutionen för geovetenskaper

    Author : John Owen Edgar; [2017]
    Keywords : Izu-Bonin; plagioclase; magma; strontium; thermobarometry; rear arc; Izu-Bonin; plagioklas; magma; strontium; termobarometri; bakbåge;

    Abstract : The Izu rear-arc volcanism was investigated by IODP EXP350 in spring 2014. A total stratigraphy of1800 m was drilled, and contains volcaniclastic material within tuffaceous mudstone. READ MORE

  3. 3. New geochronological constraints on the Klipriviersberg Group: defining a new Neoarchean large igneous province on the Kaapvaal Craton, South Africa

    University essay from Lunds universitet/Geologiska institutionen

    Author : Joaen Stamsnijder; [2017]
    Keywords : LA-ICP-MS; U–Pb geochronology; ID-TIMS; baddeleyite; Klipriviersberg Group; LIP; South Africa; Earth and Environmental Sciences;

    Abstract : In recent years, there has been a significant improvement in our ability to determine the ages of extensive short-lived magmatic events (large igneous provinces) dominated by rocks of mafic (silica-poor) compositions. This has been aided by targeting the magmatic feeders to these large igneous provinces (e.g. READ MORE

  4. 4. U-Pb baddeleyite ages from mafic dyke swarms in Dharwar craton, India : links to an ancient supercontinent

    University essay from Lunds universitet/Geologiska institutionen

    Author : Kürsad Demirer; [2012]
    Keywords : U-Pb TIMS baddeleyite; mafic dykes; Dharwar craton; palaeoreconstructions; Superia; U-Pb TIMS baddeleyit; mafiska gångar; Dharwar kraton; palaeorekonstruktion; Earth and Environmental Sciences;

    Abstract : .... READ MORE

  5. 5. First precise U-Pb ages of mafic dykes from the São Francisco Craton : initial barcoding of the São Francisco-Congo Craton

    University essay from Lunds universitet/Geologiska institutionen

    Author : Eduardo Miranda da Silveira; [2011]
    Keywords : São Francisco Craton; Congo Craton; mafic intrusions; U-Pb baddeleyite; geochronology; São Francisco kraton; Congo kraton; diabas; U-Pb; baddeleyit; geokronologi; Earth and Environmental Sciences;

    Abstract : São Francisco-kratonen i Sydamerika är en mycket gammal landmassa som bär spår av upprepade extensionella händelser då magmor från manteln transporterades uppåt och kristalliserade som diabas. Tidigare försök att åldersbestämma dessa gångbergarter är få och begränsade till radiometriska metoder som är känsliga för metamorfos och vittring. READ MORE