Sökning: "Meteorites"
Visar resultat 1 - 5 av 9 avhandlingar innehållade ordet Meteorites.
1. Mössbauer Spectroscopy of Meteoritic and Synthetic Fe-Ni Alloys
Sammanfattning : This thesis reports on the results of investigating Fe-containing minerals in meteorites, with focus on Fe-Ni minerals and their magnetic properties, along with some synthetic Fe-Ni analogues. The New Halfa meteorite, which fell in Sudan 1994, has been studied using Mössbauer spectroscopy, X-ray diffraction, and electron microprobe analysis techniques, and classified as an ordinary L-type chondrite of petrologic type 4. LÄS MER
2. Conodont biostratigraphy, taxonomy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia - with focus on meteorite and extraterrestrial chromite-rich strata
Sammanfattning : This thesis deals with conodont biostratigraphy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia, with focus on limestone strata showing traces of the ~ 470 Ma L-chondrite parent body break-up. The evidence for this cosmic event includes abundant centimeter to decimeter-sized fossil meteorites and elevated levels of sediment-dispersed extraterrestrial L-type chromite found in a stratigraphical interval corresponding to the uppermost Lenodus antivariabilis, the L. LÄS MER
3. Petrology and Geochemistry of the nakhlite meteorites : Tracking complex igneous and aqueous processes on Mars during the Amazonian
Sammanfattning : The overarching science question being addressed by this research project was the geological history of the nakhlite group of Martian meteorites as representative of a young Amazonian Martian crust. This included the magmatic processes and mechanism of emplacement at the origin of the meteorites but also the nature of a young Amazonian Martian aquifer that circulated throughout the nakhlites bedrock from its chemistry, origin and longevity. LÄS MER
4. Leave no trace: A non-destructive correlative approach providing new insights into impactites and meteorites
Sammanfattning : Impact cratering is today recognized as a fundamental geological process on all rocky bodies in the solar system. On Earth, however, processes such as plate tectonics and erosion have eradicated most craters from the geological record, or they may be buried under sediments, oceans, and vegetation. LÄS MER
5. Traces in Earth's geological record of the break-up of the L-chondrite parent body 470 Ma
Sammanfattning : This thesis deals with signatures in sediments on Earth related to the L-chondrite parent body break-up event at 470 Ma. The aim of this thesis is twofold: (1) investigate if the increased flux of extraterrestrial material to Earth, following the disruption of the L-chondrite parent body included larger, asteroid-sized bodies (2) try to develop new methods and tools for finding and classifying relict cosmic material in sediments. LÄS MER
