Essays about: "18O"

Showing result 1 - 5 of 30 essays containing the word 18O.

  1. 1. EBSD Investigation of High-Temperature Magnetite from Apatite-Iron-Oxide Deposits: Implications for the Formation of Giant Kiruna-Type Deposits

    University essay from Uppsala universitet/Mineralogi, petrologi och tektonik

    Author : Jens Henriksson; [2022]
    Keywords : Kiruna-type deposit; electron backscattered diffraction; crystal settling; Fe-O systematics; crystal alignment;

    Abstract : European iron production is to a large extent dependant on massive Kiruna type apatite-iron ore deposits. In this contribution, high-temperature magnetite samples from apatite-iron-oxide deposits are investigated by means of Electron Backscattered Diffraction. However, the origin of Kiruna-type deposits is still unresolved. READ MORE

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

    University essay from Uppsala universitet/Institutionen för geovetenskaper

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

    Abstract : 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. READ MORE

  4. 3. The Eemian Baltic Sea hydrography and paleoenvironment based on foraminiferal geochemistry

    University essay from Lunds universitet/Geologiska institutionen

    Author : Julia Chonewicz; [2020]
    Keywords : trace elements; benthic foraminifera; last interglacial; temperature reconstruction; geochemistry; Earth and Environmental Sciences;

    Abstract : I den här masteruppsatsen undersöktes geokemin i kalkskalen av bottenlevande foraminiferer från Anholt (Kattegat), Ristinge (Bälthavet) och Obrzynowo (Egentliga Östersjön), för att rekonstruera de hydrografiska förhållanden i Östersjön och paleomiljön under den senaste interglacialen (130 - 115 ka BP). De variabler som analyserades innefattade Mg/Ca, Ba/Ca och Mn/Ca samt stabila syre- och kolisotoper (δ18O och δ13C) i kombination med data från tidigare studier och modern hydrografi. READ MORE

  5. 4. Alternative oxidase respiration in the mycorrhizal fungus Laccaria bicolor

    University essay from SLU/Dept. of Forest Ecology and Management

    Author : Hilda Mikaelsson; [2019]
    Keywords : L. bicolor; mycel; ektomykorrhiza; cellandning; AOX; alternativt oxidas; cytokromoxidas; cyanid; mycelium; ectomychorriza; respiration; alternative oxidase; cytochrome oxidase; salicylhydroxamic acid; n-propyl gallate; cyanide;

    Abstract : The temperature on Earth is rising, and one of the main drivers is anthropogen-ic greenhouse gases such as carbon dioxide (CO2). The world’s forests act as carbon sinks, binding carbon into their biomass. The net carbon assimilation is determined by the uptake and release of CO2 through the processes of photo-synthesis and respiration. READ MORE

  6. 5. Exploring the physiological variables of oxygen isotope composition in chondrychthyan teeth

    University essay from Uppsala universitet/Institutionen för biologisk grundutbildning; Uppsala universitet/Institutionen för organismbiologi; Uppsala universitet/Evolutionsbiologi

    Author : Carlos Oliveira; [2019]
    Keywords : chondrichthyan; oxygen; isotope; fractionation; teeth; enameloid; dentine;

    Abstract : Since the discoveries of vertebrate bioapatite’s ability to record oxygen isotopecomposition of ambient seawater were made (Kolodny, 1983), oxygen isotopes have beenwidely used as a climatic and oceanographic proxy. The δ18OP aquatic vertebrate apatite isa function of the δ18Ow value of the ambient water, yet “vital effects” on the δ18OP compositionhave been reported previously (Venneman et al. READ MORE