Sökning: "high-silica rocks"

Hittade 3 uppsatser innehållade orden high-silica rocks.

1. 1. Origin of Silicic Magmatism at the Katla Volcano, South Iceland

   Master-uppsats, Uppsala universitet/Institutionen för geovetenskaper

   Författare :Caroline Svanholm; [2021]
   Nyckelord :Katla volcano; Iceland; high-silica rocks; oxygen isotopes; AFC processes; Vulkanen Katla; Island; kiselrika bergarter; syreisotoper; AFC-processer;

   Sammanfattning : Katla volcano, South Iceland, is a bimodal volcanic system hosting an unusual high number of silicic rocks within a basaltic rift setting. The petrogenesis of silica-rich rocks at Katla is controversial and two end-member hypotheses have been suggested. LÄS MER

3. 2. Implications of Magma and Bedrock Interaction, a Study of Xenopumice from La Palma, the Canary Islands

   Master-uppsats, Uppsala universitet/Institutionen för geovetenskaper

   Författare :Beatrice Jägerup; [2019]
   Nyckelord :La Palma; xenopumice; phreatomagmatism; whole rock geochemistry; oxygen isotopes; La Palma; felsiska xenoliter; explosiv vulkanism; geokemi; syreisotoper;

   Sammanfattning : This thesis focuses on frothy, felsic xenoliths called ‘xenopumice’, that were retrieved from La Palma during a 10–day field campaign in December 2018. There are only few descriptions of these frothty xenoliths, and a consensus on their origin has not yet been achieved. LÄS MER

4. 3. Estimating soluble arsenic and phosphorus concentrations under Precambrian oceanic conditions

   Master-uppsats, Stockholms universitet/Institutionen för geologiska vetenskaper

   Författare :Christoffer Hemmingsson; [2014]
   Nyckelord :Arsenic; Phosphorus; Co-precipitation; Precambrian; Oceanic P levels; Ferrihydrite synthesis; Distribution coefficient; Banded iron formation;

   Sammanfattning : Original estimates of phosphorus (P) concentrations in the Precambrian oceans before 1.9 Ga gave a budget of ~10-25% of modern day levels. LÄS MER