Sökning: "volcanic arc"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden volcanic arc.

1. 1. Characterising volcanic magma plumbing systems : A tool to improve eruption forecasting at hazardous volcanoes

   Författare :David A. Budd; Valentin Troll; Tod Waight; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magma plumbing; oxygen isotopes; thermobarometry; crustal assimilation; Katla; Merapi; Kelud; Toba; volcanic hazards; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : This thesis attempts to develop our understanding of volcanic magma plumbing systems and the magmatic processes that operate within them, such as fractional crystallisation, crustal partial melting, assimilation, and magma mixing. I utilise petrology, rock and mineral geochemistry, and isotope systematics to seek to improve our ability to forecast the eruptive frequency and style of active volcanoes, an aspect often lacking in current volcano monitoring efforts. LÄS MER

3. 2. Magma generation and formation of continental crust in the Izu arc

   Författare :Haochen Duan; Abigail Barker; Jaroslaw Majka; Stefan Wastegård; Kate Saunders; Susanne M. Straub; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Oceanic arc; Izu rear-arc; Melt inlcusions; Oxygen isotopes; Boron isotopes; Continental crust; Mantle hererogeneity; In-situ microanalysis; IMS-1280; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : The Izu oceanic arc is produced by the subduction of the Pacific Sea Plate beneath the Philippine Sea Plate. The proto-Izu oceanic arc was initially formed at ca. 50 Ma, then it was separated into the Kyushu-Palau and Izu arc by the extension of the Shikoku basin from ca. 25 Ma. LÄS MER

4. 3. The genetic relationship between rhyolitic volcanism and Zn-Cu-Au deposits in the Maurliden volcanic centre, Skellefte district, Sweden : volcanic facies, lithogeochemistry and geochronology

   Författare :Cecilia Montelius; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Malmgeologi; Ore Geology;

   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

5. 4. Volcanic stratigraphy and hydrothermal alteration of the Petiknäs south Zn-Pb-Cu-Au-Ag volcanic-hosted massive sulfide deposit, Sweden

   Författare :Denis Schlatter; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ore Geology; Malmgeologi;

   Sammanfattning : The Skellefte district is one of the most important mining regions in Sweden and Europe. The district contains more than 85 pyritic Zn-Cu-Au-Ag massive sulfide deposits. LÄS MER

7. 5. Magma-Crust Interaction at Subduction Zone Volcanoes

   Författare :Ester M. Jolis; Valentin R Troll; Silvio Mollo; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; magma-crust interaction; stable isotopes O-C ; radiogenic isotopes Sr-Nd-Pb ; calc-silicate xenoliths; HP-HT experimental petrology; crustal volatiles; Vesuvius; Merapi; Kelut; the Sunda arc; Geovetenskap med inriktning mot mineralogi; petrologi och tektonik; Earth Science with specialization in Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : The focus of this work is magma-crust interaction processes and associated crustal volatile release in subduction zone volcanoes, drawing on rock, mineral, and gas geochemistry as well as experimental petrology. Understanding the multitude of differentiation processes that modify an original magma during ascent to the surface is vital to unravel the contributions of the various sources that contribute to the final magmas erupted at volcanoes. LÄS MER