Sökning: "Subduction"

Visar resultat 21 - 25 av 40 avhandlingar innehållade ordet Subduction.

1. 21. Cryptic Orogeny : uplift of the Al Hajar Mountains at an alleged passive margin

   Författare :Reuben Johannes Hansman; Ring Uwe; Joachim Jacobs; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; uplift; mountains; structural; low-temperature; thermochronology; dating; fission-track; U-Th He; U-Pb; calcite; structure-from-motion; photogrammetry; UAV; trishear; fault-propagation; Hafit; Al Hajar Mountains; United Arab Emirates; Oman; Geology; geologi;

   Sammanfattning : Mountains evolve and grow because of the large forces that occur from the collision of tectonic plates. Plate boundaries change and move through time, and regions that were once stable, shallow-marine environments can be dragged into subduction zones and get transformed into vast mountain ranges. LÄS MER

3. 22. Statistical Seismology Studies in Central America : b-value, seismic hazard and seismic quiescence

   Författare :David Aníbal Monterroso Juárez; Ota Kulhánek; Stefan Wiemer; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geophysics; b-value; seismic hazard; Monte Carlo; seismic quiescence; Central America; stress; Geofysik; Geophysics; Geofysik;

   Sammanfattning : The present thesis collects results of research applying theory and methods of statistical seismology to the seismicity of Central America, a region with a complex tectonic setting controlled by the interaction of four major plates, namely the Caribbean, Cocos, Nazca and North American plates.Three different earthquake catalogues were used for studies focused on stress in a tectonic volume, seismic hazard maps and seismicity patterns (precursors), covering the region 94ºW to 81ºW and 5ºN to 20ºN. LÄS MER

4. 23. On the origin and evolution of the palaeoproterozoic Aitik Cu-Au-Ag deposit, northern Sweden : a porphyry copper-gold ore, modified by multistage metamorphic-deformational, magmatic-hydrothermal, and IOCG-mineralizing events

   Författare :Christina Wanhainen; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

   Sammanfattning : The Aitik Cu-Au-Ag mine in the Gällivare area in northern Sweden is the biggest open pit operation in northern Europe and one of Europe’s largest metal producers. The open pit is almost 3 km long, 930 m wide and 345 m deep. Approximately 424 million tonnes of ore averaging 0.4% Cu, 0. LÄS MER

5. 24. The Mesoproterozoic Hallandian event - a region-scale orogenic event in the Fennoscandian Shield

   Författare :Linus Brander; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fennoscandian Shield; Hallandian orogeny; Eastern Segment; Protogine Zone; U-Pb geochronology; zircon; baddeleyite; Nd-isotopes; Hf-isotopes; tectonic model;

   Sammanfattning : The Sveconorwegian Province occupies the southwestern part of the Fennoscandian Shield. The easternmost tectonic unit of the Province is the 1710-1660 Ma parautochthonous Eastern Segment, which bears the imprint of at least two metamorphic events; the 1460-1380 Ma Hallandian and the 1150-970 Ma Sveconorwegian. LÄS MER

7. 25. Geophysical studies of the upper crust of the central Swedish Caledonides in relation to the COSC scientific drilling project

   Författare :Peter Hedin; Christopher Juhlin; Alireza Malehmir; Bjarne Almqvist; Charles Hurich; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; reflection seismic; collisional orogeny; Scandinavian Caledonides; COSC; scientific drilling; geophysical logging; gravity; magnetics; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Sammanfattning : The Collisional Orogeny in the Scandinavian Caledonides (COSC) project aims to provide a deeper understanding of mountain belt dynamics through scientific deep drilling in the central parts of the mountain belt of western Sweden. The main targets include a subduction related allochthon, the basal orogenic detachment and the underlying partially subducted Precambrian basement. LÄS MER