Sökning: "Laurentia"
Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet Laurentia.
1. The tectonic evolution of northwest Svalbard
Sammanfattning : Svalbard represents the uplifted and exhumed northwest corner of the Barents Sea Shelf. Pre-Carboniferous rocks of Svalbard are divided into the Eastern, Northwestern and Southwestern Terranes, were amalgamated during the Caledonian Orogen and are separated by north-south-trending strike-slip faults. LÄS MER
2. Magnetic anisotropy and paleomagnetism of precambrian rocks in the Fennoscandian shield
Sammanfattning : This thesis presents three applications of the anisotropy of magnetic susceptibility (AMS) technique, dealing with tectonic and magmatic flow fabrics of Proterozoic igneous rocks in the central and northern parts of the Fennoscandian Shield. Paleomagnetic measurements were performed in attempts to put the different rock units into a geological and plate tectonic context. LÄS MER
3. The West Ny Friesland Terrane : An exhumed mid-crustal obliquely convergent orogen : by Patrik W. Nilsson
Sammanfattning : Ny Friesland, in northeastern Svalbard, is the type-area for transpressive orogeny. The West Ny Friesland Terrane (WNT) is composed of a c. 12 km thick basal succession of amphibolite-grade schists and gneisses, previously thought to be the lower of a c. 20 km thick succession of concordant, volcano-sedimentary strata. LÄS MER
4. Evolution and taxonomy of Cambrian arthropods from Greenland and Sweden
Sammanfattning : Arthropods have a rich fossil record spanning the Phanerozoic. Biomineralized forms such as the extinct trilobites are particularly common and are proven index fossils for biostratigraphy. Forms with an unmineralized cuticle are more rare, preserved only in so called konservat lagerstätten. LÄS MER
5. Tectonic evolution of NW Svalbard
Sammanfattning : The Neoproterozoic is a remarkable era in Earth’s history with dramatic variations in climate and biota, possibly resulting in global glaciations events (eg. “snowball earth”, Kirschvink, 1992) and the first appearance of metazoans (Conway Morris, 1993). LÄS MER