کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4733324 1640541 2012 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Magmatic to solid state fabrics in syntectonic granitoids recording early Carboniferous orogenic collapse in the Bohemian Massif
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Magmatic to solid state fabrics in syntectonic granitoids recording early Carboniferous orogenic collapse in the Bohemian Massif
چکیده انگلیسی

The ∼354–336 Ma Central Bohemian Plutonic Complex is a Variscan magmatic arc that developed in the central Bohemian Massif in response to subduction of the Saxothuringian lithosphere beneath the Teplá–Barrandian microplate. Magmatic to solid state fabrics in the most voluminous portion of this arc (the ∼346 Ma Blatná pluton) record two superposed orogenic events: dextral transpression associated with arc-parallel stretching and arc-perpendicular shortening, and normal shearing associated with exhumation of the high-grade core of the orogen (Moldanubian unit). This kinematic switch is an important landmark in the evolution of this segment of the Variscan belt for it marks the cessation of subduction-related compressive forces in the upper crust giving way to gravity-driven normal movements of the Teplá–Barrandian hanging wall block relative to the high-grade Moldanubian footwall. We use thermal modeling to demonstrate that the emplacement of huge volumes of arc magmas and their slow cooling produced a thermally softened domain in the upper crust and that the magmatic arc granitoids may have played a major role in initiating the orogenic collapse in the Bohemian Massif through lubrication and reactivation of a pre-existing lithospheric boundary and decreasing the overall strength of the rigid orogenic lid.

Figure optionsDownload high-quality image (236 K)Download as PowerPoint slideHighlights
► Central Bohemian Plutonic Complex is a Variscan magmatic arc in the Bohemian Massif.
► Fabrics in high-K calc-alkaline granodiorites record two superposed orogenic events.
► Switch from subduction-related forces to gravity tectonics in the Bohemian Massif.
► Modeling demostrates that voluminous magmas produced a weak domain in the upper crust.
► Overall strength dropped leading to collapse of the upper-crustal layer.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Geology - Volume 36, March 2012, Pages 27–42
نویسندگان
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