Sökning: "Lower Jurassic"
Visar resultat 6 - 10 av 12 uppsatser innehållade orden Lower Jurassic.
6. 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 institutionenSammanfattning : 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
7. A Phylogenetic Appraisal of Pachycormus bollensis: Implications for Pachycormiform Evolution
Kandidat-uppsats, Institutionen för geovetenskaperSammanfattning : The Pachycormiformes were a successful group of stem-teleosts. Although they persisted for more than 100 million years in the Mesozoic seas and occupied a significant space of the ecosystem, little is known about this most diverse group. One of the earliest pachycormiformes is the lower Jurassic Pachycormus bollensis. LÄS MER
8. Mapping of Lower Cretaceous (Knurr Sandstone) turbidite lobes using Seismic Stratigraphy and prospectivity along the southern Loppa High Margin, Hammerfest Basin, Barents Sea, Norway
Master-uppsats, GeofysikSammanfattning : The Hammerfest Basin was formed through downfaulting in Late Jurassic-Early Cretaceous times, allowing the deposition and preservation of Jurassic sediments which later were covered by thick Cretaceous sequences filling in the basin. This study has been conducted along the southern margin of the Loppa High to develop a complete sequence stratigraphic framework and to map Early Cretaceous Knurr Formation turbidite lobes along the slope of the High. LÄS MER
9. Palynostratigraphy and palaeoclimatic analysis of Lower-Middle Jurassic (Pliensbachian - Bathonian) of the Inner Hebrides, NW Scotland
Magister-uppsats, Lunds universitet/Geologiska institutionenSammanfattning : A palynostratigraphic investigation of partly ammonite dated, Pliensbachian to Bathonian (Early – Middle Jurassic) strata on the Isles of Skye and Raasay, Inner Hebrides in Northwest Scotland, has recovered a diverse but not always well preserved miospore flora and a less diverse dinoflagellate cysts flora. The studied interval has been subdivided into five biozones, A - E, based on the first occurrence, common occurrence, first common occurrence, and relative abundance of pollen and spore key taxa. LÄS MER
10. Extraterrestrisk och terrestrisk kromrik spinell i fanerozoiska kondenserade sediment
Magister-uppsats, Lunds universitet/Geologiska institutionenSammanfattning : This study aims to assess the normal inflow of extraterrestrial chromite to Earth. The results from the investigation are compared to earlier studies of middle Ordovician Orthoceratite Limestone in which 1 - 3 extraterrestrial chromite grains ( >63 ƒÊm ) per kilogram limestone were found. LÄS MER
