Sökning: "3He anomalies"

Hittade 2 avhandlingar innehållade orden 3He anomalies.

  1. 1. The micrometeorite flux to Earth through the Phanerozoic Eon : Reconstructed using sediment-dispersed extraterrestrial spinels

    Författare :Ellinor Martin; Kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chromite; chrome spinel; micrometeorites; Phanerozoic; asteroid breakup; ordinary chondrites; 3He anomalies; lunar impacts; ice age; impact craters; zircons;

    Sammanfattning : The purpose of this thesis is to add an astronomical component to the history and evolution of Earth by reconstructing the micrometeorite flux to Earth at different time intervals during the Phanerozoic Eon, using sediment-dispersed extraterrestrial spinel group minerals as a proxy. Chromite and chrome spinel are common refractory members of the spinel group, occurring in both extraterrestrial and terrestrial rocks. LÄS MER

  3. 2. The flux of extraterrestrial spinels to Earth associated with He-3 anomalies in Cenozoic and Ordovician sediments

    Författare :Samuele Boschi; Kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Chromite; He-3 anomaly; Cenozoic; mid-Ordovician; asteroid breakup; ordinary chondrites; Popigai ejecta; iridium anomaly; Zircons; ice age;

    Sammanfattning : The main goal of this thesis is to reconstruct the flux of extraterrestrial matter to Earth in specific time intervals of our past in order to add an astronomical dimension to the understanding of Earth's history. To accomplish this, extraterrestrial chrome-spinel grains have been extracted and analysed. LÄS MER