Search for dissertations about: "sulfur isotope"

Showing result 1 - 5 of 6 swedish dissertations containing the words sulfur isotope.

2. 1. Origin of volcanic sulfur in Iceland : a sulfur isotope study

   Author : Peter Torssander; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : The chemistry and sulfur isotope composition have been determined in fresh and altered rocks and geothermal fluids in Iceland. Sulfur isotope ratios were analysed in 27 selected volcanic rocks, eight lava incrustations and three volcanic gas samples.The 63% of the basalts ranges from -2.0 o/oo to + 0. READ MORE

4. 2. Varved lake sediments and diagenetic processes

   Author : Veronika Gälman; Ingemar Renberg; Daniel Conley; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Varved annually laminated lake sediment; diagenesis; varve appearance; iron; sulfur; chemical speciation; iron cycling; carbon; nitrogen; stabile isotopes; δ13C; δ15N; Earth sciences; Geovetenskap;

   Abstract : Varved (annually laminated) sediments are of great interest for inference of past environmental conditions, as they provide dated records with high time resolution. After deposition, the sediment varves are affected by diagenesis; i.e., chemical, physical and biological changes that occur within the sediment. READ MORE

5. 3. Utilizing a tectonic framework to constrain the mineral system and remobilization in the Kiruna mining district, Sweden

   Author : Leslie Logan; Tobias E. Bauer; Fernando Tornos; Olof Martinsson; Paul Evins; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Kiruna; tectonic framework; mineral system; IOCG; IOA; remobilization; sulfur isotopes; trace elements; geochronology; Pahtohavare; Viscaria; Rakkurijärvi; Malmgeologi; Ore Geology;

   Abstract : The Kiruna mining district, located in the northern Norrbotten ore province, Sweden, is a geologically and economically important area, being the type-locality for Kiruna iron oxide-apatite (IOA) deposits and also host to a variety of other deposits including syngenetic stratiform exhalative Cu-(Fe-Zn) (Viscaria, Eastern Pahtohavare), epigenetic stratabound Cu ± Au (Pahtohavare), and iron oxide-copper-gold (IOCG, Rakkurijärvi) deposits. However, the timing of IOA versus IOCG within the tectonic evolution is in question based on structural investigations showing Cu- and Fe-sulfides occur in late-orogenic structures. READ MORE

6. 4. Formation, uptake and bioaccumulation of methylmercury in coastal seas : a baltic sea case study

   Author : Aleksandra Skrobonja; Erik Björn; Agneta Andersson; Anne L. Soerensen; Marc Amyot; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mercury; methylmercury; bioaccumulation; mesososm; isotope tracers; methylation; demethylation; stability constant; kinetic model; coastal sea; ICPMS; LC-MS MS;

   Abstract : Methylmercury (MeHg) is a potent neurotoxin which can bioaccumulate to harmful levels in aquatic food webs. Methylmercury formation is a predominantly biotic process which involves phylogenically diverse microorganisms (e.g. iron- or sulfate-reducing bacteria). READ MORE

7. 5. The geology and genesis of lead-zinc veins in Sweden

   Author : Åke Johansson; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : The geology and genesis of Pb-Zn-bearing vein deposits in Sweden have been studied through investigations of their geological setting, vein and alteration mineralogy, wall rock geochemistry, lead and sulfur isotope composition and sphalerite composition, and through thermometric measurements on fluid inclusions from selected veins. The investigated deposits include Subjotnian veins from Älvdalen, Dalslandian veins from Dalsland and Värmskog, Caledonian quartz and calcite veins, Devonian deposits in the Siljan Ring structure, and Variscan veins in SE Scania. READ MORE