Sökning: "Allocladus helgei"

Hittade 2 uppsatser innehållade orden Allocladus helgei.

  1. 1. The Jurassic extinction events and its relation to CO2 levels in the atmosphere : a case study on Early Jurassic fossil leaves

    Kandidat-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Liina Santasalo; [2013]
    Nyckelord :conifers; Pliensbachian; Australian; Early Jurassic; stomatal proxy; palaeo-CO2; koldioxidhalt; klimat; Australien; tidig Jura; Marburg subgroup; Allocladus helgei; stomata index; CO2; Earth and Environmental Sciences;

    Sammanfattning : The Mesozoic was a so-called “hothouse” time period in Earth’s history, with high concentrations of atmospheric CO2 and elevated temperatures, but the exact climate evolution is not fully known for the entire inter-val. The Early Jurassic for instance is believed to have been a warm period, flanked by two episodes of extremely high CO2, coinciding with environmental degradation and mass extinctions: the Triassic-Jurassic (200 Ma) and the early Toarcian (183 Ma) mass extinction events. LÄS MER

  2. 2. An Early Jurassic conifer-dominated assemblage of the Clarence-Moreton Basin, eastern Australia

    Magister-uppsats, Lunds universitet/Geologiska institutionen

    Författare :Ida-Maria Jansson; [2006]
    Nyckelord :Australia; Jurassic; Marburg Subgroup; conifers; palaeoenvironment; Australien; Jura; barrträd; palaeomiljö; Earth and Environmental Sciences;

    Sammanfattning : During the early Mesozoic two mass-extinction events profoundly reshaped the world’s biota. The first of these took place at the end of the Triassic and affected both marine organisms and terrestrial floras. The second occurred as an oceanic anoxic event during the early Toarcian. LÄS MER