Record details

Title
    Magnetic fabric and tectonic setting of the Early to Middle Jurassic felsic dykes at Pitt Point and Mount Reece, eastern Graham Land, Antarctica
Author
    Janoušek, Vojtěch
    Soejono, Igor
    Venera, Zdeněk
    Žák, Jiří
Language
    anglicky
Publication type
    článek v periodiku
Source title - serial
    Antarctic Science
Vol./nr.
    Roč. 24, č. 1
Pages
    14
Year
    2012
Thesaurus term
    Anisotropy of magnetic susceptibility (AMS), Antarctic Peninsula, Chon Aike silicic large igneous province, Gondwana break-up, regional extension, Trinity Peninsula Group
Keyword
    Antarctica
    Dykes
    Early
    Eastern
    Fabric
    Felsic
    Graham
    Jurassic
    Land
    Magnetic
    Middle
    Mount
    Pitt
    Point
    Reece
    Setting
    Tectonic
Abstract (in english)
   At Pitt Point, the east coast of Graham Land (Antarctic Peninsula), the Early to Middle Jurassic (Toarcian-Aalenian) rhyolite dykes form two coevally emplaced NNE-SSW and E-W trending sets. The nearly perpendicular dyke sets define a large-scale chocolate-tablet structure, implying biaxial principal extension in the WNW-ESE and N-S directions. Along the nearby north-eastern slope of Mount Reece, the WNW-ESE set locally dominates suggesting variations in the direction and amount of extension. Magnetic fabric in the dykes, revealed using the anisotropy of magnetic susceptibility (AMS) method, indicates dip-parallel to dip-oblique (?upward) magma flow. The dykes are interpreted as representing sub-volcanic feeder zones above a felsic magma source. The dyke emplacement was synchronous with the initial stages of the Weddell Sea opening during Gondwana break-up, but it remains unclear whether it was driven by regional stress field, local stress field above a larger plutonic body, or by an in
   teraction of both.
Contributor
    Česká geologická služba
Contributor code
    ČGS (RIV)
Source format
    R
Import date
    15. 10. 2014