Sökning: "magma evolution"
Visar resultat 11 - 15 av 15 avhandlingar innehållade orden magma evolution.
11. The genetic relationship between rhyolitic volcanism and Zn-Cu-Au deposits in the Maurliden volcanic centre, Skellefte district, Sweden : volcanic facies, lithogeochemistry and geochronology
Sammanfattning : The Skellefte district is one of three major ore provinces in Sweden and contains more than 80 Zn-Cu-Au-Ag massive sulphide deposits. The Maurliden area in the central part of the district represents a subaqueous, constructional and relatively topographic high silicic volcanic centre. LÄS MER
12. U-Pb baddeleyite geochronology of Precambrian mafic dyke swarms and complexes in southern Africa - regional scale extensional events and the origin of the Bushveld Complex
Sammanfattning : Dolerite dykes are formed when iron- and magnesium-rich (mafic) mantle-derived magmas ascend through the lithosphere (upper part of the mantle) and crystallize as ‘hydro-fractures’ within the crust. Dykes may exist in great numbers to form dyke swarms (linear or radiating), which can be linked to time periods of continental break-up, or attempted break-up events, associated with voluminous volcanism. LÄS MER
13. Glacial Isostatic Adjustment : Inferences on properties and processes in the upper mantle from 3D dynamical modeling
Sammanfattning : Observations of glacial isostatic adjustment (GIA) offers a powerful window into the properties of the Earth's interior. Combined with dynamical modeling of the GIA process we can use the observations to infer properties such as the elastic structure of the lithosphere, the rheology of the mantle and changes in the stress conditions in the Earth. LÄS MER
14. The Älgträsk intrusion-related Au (Cu, Zn) deposit, Skellefte district, northern Sweden : Relationships between ore forming events in the Palaeoproterozoic Jörn intrusive complex
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
15. The origin of iron ores in Bergslagen, Sweden, and their relationships with polymetallic sulphide ores
Sammanfattning : The Bergslagen mining district of southern Sweden is one of Europe’s classic mining districts with more than 1 000 years of mining history. One of the typical features of Bergslagen is a spatial association between Zn-Pb-Ag-(Cu-Au) sulphide deposits and magnetite-rich Fe oxide deposits. LÄS MER
