Essays about: "spinell"

Found 4 essays containing the word spinell.

  1. 1. Cr-spinels in the Franklinian Mobile Belt : a geochemical record of Paleozoic tectonics

    University essay from Stockholms universitet/Institutionen för geologiska vetenskaper

    Author : Malvina Forbes Halldén; [2019]
    Keywords : geology; geochemistry; spinel; Cr-spinel; chromite; SEM; scanning electron microscope; electron microprobe; EMP; electron probe microanalyzer; EPMA; electron micro probe analyzer; EMPA; petrogenetic indicator; microscopy; alteration; Franklinian Mobile Belt; Kulutingwak Formation; Clements Markham fold belt; Pearya; Paleozoic; suprasubduction zone; SSZ; island arc; IA; Arctic Canadian Archipelago; Ellesmere Island; Canada; 2017 Circum-Arctic Structural Events Expedition 19; Memorial University of Newfoundland; geologi; geokemi; spinell; Cr-spinell; kromit; SEM; svepeletronmikroskopi; elektronmikrosondanalys; EMP; EPMA; EMPA; petrogenetisk indikator; mikroskopi; Franklinian Mobile Belt; Kulutingwak-formationen; Clements Markham fold belt; Pearya; Paleozoikum; suprasubduktionszon; SSZ; öbåge; IA; Kanadas arktiska öar; Ellesmereön; Kanada; 2017 Circum-Arctic Structural Events Expedition 19; Memorial University of Newfoundland;

    Abstract : The chemical compositions of Cr-spinel extracted from mafic and ultramafic rocks collected on Ellesmere Island in the Arctic Canadian Archipelago were obtained through electron microprobe analyses. The extensively altered rocks are sampled from rock units in the Franklinian MobileBelt, which is representative of a Paleozoic tectonically active oceanic regime of which little is presently known. READ MORE

  2. 2. When did the Kalahari craton form? : constraints from baddeleyite U-Pb geochronology and geo-chemistry of mafic intrusions in the Kaapvaal and Zimbabwe cratons

    University essay from Lunds universitet/Geologiska institutionen

    Author : Nadine März; [2010]
    Keywords : geography; geology; Kalahari craton; baddeylite U-Pb geochronology; mafic intrusions; Kaapvaal craton; Zimbabwe craton; Earth and Environmental Sciences;

    Abstract : Nordost om Bushveldkomplexen i Kaapvaal kratonen finns en mäktig gångsvärm av nordost-orienterade diabasgångar tillhörande ”the Black Hills dyke swarm”. Med hjälp av U- Pb metoden av mineral baddeleyit daterades fem gångar inom ålderspannet 1.87 - 1.85 Ga, där två av dem ger exakta åldrar på 1852 ± 5 Ma och 1863 ± 7 Ma. READ MORE

  3. 3. A geochemical characterization of the lower part of the Miocene shield-building lavas on Gran Canaria

    University essay from Lunds universitet/Geologiska institutionen

    Author : Romina Peetz; [2009]
    Keywords : Gran Canaria; shield-building lavas; Güigüi Formation; Earth and Environmental Sciences;

    Abstract : Ocean islands offer a great potential to provide information about mantle processes and the composition of the mantle. Gran Canaria is located in the centre of the Canary Island Archipelago and is well suited for such studies. A comprehensive study of the lower Miocene shield-building lavas is performed for this thesis. READ MORE

  4. 4. Spinel group minerals in carbonaceous and ordinary chondrites

    University essay from Lunds universitet/Geologiska institutionen

    Author : My Riebe; [2009]
    Keywords : spinel group minerals; carbonaceous chondrites; ordinary chondrites; spinellgruppmineral; kolkondriter; ordinära kondriter; Earth and Environmental Sciences;

    Abstract : Meteorites are easily altered in the oxygen-rich environment on the Earth surface. Fossil meteorites are thus uncommon and in the ones, which are found, almost all minerals are secondary. However, the spinel group mineral chromite is resistant to alteration and has successfully been used as a proxy for ordinary chondrites in sediment. READ MORE