Sökning: "KBAR"

Visar resultat 1 - 5 av 14 avhandlingar innehållade ordet KBAR.

1. 1. How were high-pressure rocks exhumed in Naxos, Greece?

   Författare :Alexandre Peillod; Uwe Ring; Johannes Glodny; Alasdair Skelton; Joakim Mansfeld; Jaroslaw Majka; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; extrusion wedge Naxos petrology metamorphism; Mineralogy; Petrology and Geochemistry; mineralogi; petrologi och geokemi;

   Sammanfattning : Combining petrological and geochronological data we were able to show that rocks in south Naxos completed a full blueschist-/greenschist-facies metamorphic loop in about 10 Myr, distinctly faster than hitherto believed. We show that the high-pressure rocks reached peak pressure (16.3±0.9 kbar - 619 ±32°C) between 40. LÄS MER

3. 2. Disturbance of Pb, Sr, and Nd isotope systems related to medium and low grade metamorphism illustrated with data from the polymetamorphic Early Proterozoic (Rombak) - Sjangeli basement window of the Caledonides of Northern Sweden

   Författare :Rolf Romer; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied Geology; Tillämpad geologi;

   Sammanfattning : The Sjangeli supracrustal belt forms the easternmost belt of a series approximately N-S striking, steeply dipping Early Proterozoic belts of the Rombak-Sjangeli basement window, which formed in an island arc setting. The volcanic units of the Sjangeli area consist of metatuffs, which contain abundant Cu-mineralizations, metalava flows and pillowed metalavas and are intercalated with banded carbonatesilicate rocks and micaschists, which contain various amounts of volcanic material. LÄS MER

4. 3. The metamorphic history of Naxos (central Cyclades, Greece) : Deciphering the Oligocene and Miocene exhumation events

   Författare :Alexandre Peillod; Uwe Ring; Alasdair Skelton; Arne Willner; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cycladic Blueschist Unit; exhumation; fluid flow; geothermobarometry; Hellenide orogen; Rb-Sr dating; subduction-zone metamorphism; Heat flow; Lower crust; extensional domain; Metamorphic core complex; Geology; geologi;

   Sammanfattning : High pressure, low temperature (HP-LT) rocks observed at the surface of the Earth are evidence ofpast subduction zones. Understanding the tectonics processes that control the exhumation of HP-LT metamorphic rocks in these subduction zones requires full comprehension of the pressure-temperature-time (P–T–t) cycle that the rocks experienced. LÄS MER

5. 4. Hydrogen in nominally anhydrous silicate minerals : Quantification methods, incorporation mechanisms and geological applications

   Författare :Franz A. Weis; Henrik Skogby; Peter Lazor; Jannick Ingrin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NAMs; clinopyroxene; hydrogen; hydrothermal pressure; magmatic water content; zoisite; OH-dipole; Raman spectroscopy; FTIR; luminescence; proton-proton scattering;

   Sammanfattning : The aim of this thesis is to increase our knowledge and understanding of trace water concentrations in nominally anhydrous minerals (NAMs). Special focus is put on the de- and rehydration mechanisms of clinopyroxene crystals in volcanic systems, how these minerals can be used to investigate the volatile content of mantle rocks and melts on both Earth and other planetary bodies (e. LÄS MER

7. 5. Pan-African and Red Sea tectonics of eastern Eritrea

   Författare :Woldai Ghebreab; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Pan-African tectonic grain; Geovetenskap; Earth sciences; Geovetenskap; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

   Sammanfattning : This thesis proposes that the Pan-African tectonic grain in eastem Eritrea influenced theCenozoic opening of the Red Sea. Evidence is based on studies of the structures and fabrics of various phases associated with both the Pan-African orogeny and subsequent Red Sea extension. LÄS MER