Sökning: "Alasdair Skelton"

Visar resultat 6 - 10 av 17 avhandlingar innehållade orden Alasdair Skelton.

  1. 6. How do metamorphic fluids move through rocks? : An investigation of timescales, infiltration mechanisms and mineralogical controls

    Författare :Barbara I. Kleine; Alasdair D. L. Skelton; John C. Schumacher; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Metamorphic fluid flow; fluid-rock interaction; fluid infiltration mechanisms; fluid flux rates; thermodynamic modeling; reaction front propagation; fluid flux calculation; Geology; geologi;

    Sammanfattning : This thesis aims to provide a better understanding of the role of mountain building in the carbon cycle. The amount of CO2 released into the atmosphere due to metamorphic processes is largely unknown. LÄS MER

  3. 7. Fluid-induced alteration of metasedimentary rocks in the Scottish Highlands

    Författare :Alexander Lewerentz; Alasdair Skelton; Patrick Crill; Charlotte Möller; Jay Ague; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; metamorphic fluids; metamorphic fluid flow; fluid-rock interaction; metamorphic fluid fluxes; Geology; geologi;

    Sammanfattning : Fluids, mainly H2O and CO2, are released from H- and C-bearing phases during prograde metamorphism. Because of the buoyancy of these fluids, they rise within the crust towards the surface of the Earth. Metamorphic fluids take advantage of permeable horizons, shear zones, fold hinges, fractures, and are channelled into high-flux zones. LÄS MER

  4. 8. Vein controlled crystal size distributions of Barrovian index minerals

    Författare :Alexander Lewerentz; Alasdair Skelton; Uwe Ring; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The concept of index mineral based metamorphic zones was first introduced by George Barrow in 1912, and Barrovian metamorphism is still applied by metamorphic petrologists. Today the importance of metamorphic fluids for driving metamorphic reactions is widely recognised. LÄS MER

  5. 9. Volcanism at the tip of a propagating rift : the Heimaey volcanic centre, south Iceland

    Författare :Hannes B. Mattsson; Armann Höskuldsson; Alasdair Skelton; Sigurdur Steinthorsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geology; Volcanology; Petrology; Heimaey; Vestmannaeyjar; Propagating rift; Phreatomagmatic; Diatreme; Tumuli; Earth sciences; Geovetenskap;

    Sammanfattning : Primary magmas are generated by 4-6% partial melting near the garnet-spinel stability fields beneath Heimaey (i.e. 80-65 km depth). The magmas fractionate 31% olivine and clinopyroxene en-route to ponding at the base of the crust (and forming a parental Vestmannaeyjar magma). LÄS MER

  7. 10. Chemical and isotopic records of polycyclic histories in a subducted continental crust (Dora-Maira Massif, Western Alps)

    Författare :Francesco Nosenzo; Paola Manzotti; Alasdair Skelton; Charlotte Möller; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Subduction; continental crust; polycyclic; garnet; metamorphic petrology; Geology; geologi;

    Sammanfattning : At convergent plate margin, part of the continental crust can be subducted and exhumed. During continental subduction a pre-existing crust is reworked. Remnants of an older orogen are recycled and subjected to (ultra)-high-pressure metamorphism. LÄS MER