Sökning: "Palaeoproterozoic"

Visar resultat 1 - 5 av 21 avhandlingar innehållade ordet Palaeoproterozoic.

1. 1. Origin of the Kleva Ni-Cu sulphide mineralisation in Småland, southeast Sweden

   Författare :Karolina Bjärnborg; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Palaeoproterozoic; Fennoscandia; geochronology; geochemistry; sulphide remobilisation; gabbro–diorite; mantle; arc; ore genesis; Ni-Cu sulphide deposit;

   Sammanfattning : The Kleva Ni-Cu sulphide deposit is situated within a gabbro-diorite intrusive complex in southeast Sweden. The basement north of the intrusive complex is dominated by 1.81–1.77 Ga granites of the Palaeoproterozoic Transscandinavian Igneous Belt (TIB). LÄS MER

3. 2. The Älgträsk intrusion-related Au (Cu, Zn) deposit, Skellefte district, northern Sweden : Relationships between ore forming events in the Palaeoproterozoic Jörn intrusive complex

   Författare :Therese Bejgarn; Hartwig Frimmel; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

   Sammanfattning : Palaeoproterozoic intrusion hosted and intrusion related deposits such as the Älgträsk Au±Cu±Zn, Åkerberg Au, Älgliden Cu–Ni±Au, and the porphyry style Järvträsk Cu±Mo±Zn, Granberg Cu±Mo and Tallberg Cu–Au±Mo deposits are situated in the northern part of the Skellefte District, northern Sweden. These deposits are all hosted within the oldest unit of the Jörn intrusive complex (JIC). LÄS MER

4. 3. Geological Evolution of the Supracrustal Palaeoproterozoic Hamrånge Group: A Svecofennian Case Study

   Författare :Erik Ogenhall; Håkan Sjöström; Hans Annersten; Markku Väisänen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hamrånge; Ljusdal; Hagsta Gneiss Zone; geochemistry; geochronology; thermobarometry; metamorphism; fold-thrust belt.; Earth sciences; Geovetenskap; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : The work presented in this thesis utilizes several geological methods to investigate the origin and evolution of the supracrustal rocks in the Palaeoproterozoic Hamrånge Group (HG) in the south-central Swedish Svecofennian. The first paper is based on whole-rock geochemistry to show the plate tectonic setting of volcanic rocks within the HG. LÄS MER

5. 4. Validating the existence of the supercraton Vaalbara in the Mesoarchaean to Palaeoproterozoic

   Författare :Ashley Gumsley; Berggrundsgeologi; []
   Nyckelord :Vaalbara; Kaapvaal Craton; Pilbara Craton; U-Pb geochronology; paleomagnetism; supercontinent; large igneous province; dyke swarm; sill province;

   Sammanfattning : In this thesis, the longevity and continuity of the Vaalbara supercraton is addressed in six papers aimed at placing new temporal and spatial constraints onthe supercraton in the Mesoarchean to Paleoproterozoic. It has been speculated since the 1960’s that the Kaapvaal Craton in southern Africa, together withthe Pilbara Craton in Western Australia existed as a single landmass during the Precambrian – the Vaalbara supercraton. LÄS MER

7. 5. Sedimentology and detrital zircon age distribution in the Palaeoproterozoic Västervik Basin, SE Sweden

   Författare :Lena Sultan; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : .... LÄS MER