کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8911528 | 1638616 | 2018 | 68 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Geochronology, petrogenesis and geodynamic significance of the Visean igneous rocks in the Central Sudetes, northeastern Bohemian Massif
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
New sensitive high-resolution ion microprobe (SHRIMP) UPb zircon geochronologic data, whole-rock geochemical and Sr-Nd-Pb isotopic data, and zircon and quartz δ18O isotopic data from the Staré MÄsto granitoids (SMG), Jawornik granitoids (JG), and KÅodzko-ZÅoty Stok granitoids (KZSG) and associated mafic and ultramafic rocks are examined. This study provides new insights into the processes of magma generation, transport and emplacement during the Variscan development of the contact zone of the Saxothuringia, Teplá-Barrandia and Brunovistulia in the Central European portion of the Variscan belt. The results of this study, combined with existing geochemical and isotopic data, imply that the parental magmas of these intrusions share a close affinity and suggest that these intrusions formed in a subduction-related tectonic setting. The SMG, JG and KZSG magmas represent hybrids that formed from the contamination of partial melts from the lower crust and/or subducted sediments with various proportions of enriched mantle-derived melts. These mainly sheeted plutons intruded along the main geological boundaries during the Visean and recorded the vertical and lateral displacements between the major tectono-stratigraphic units (microplates) in the NE Bohemian Massif. In the Central Sudetes, these granitoid magmas were first emplaced along the northern continuation of the Moldanubian Zone. The SHRIMP UPb dating of zircons indicates that the SMG intruded the reactivated suture zone between the Brunovistulia and Saxothuringia at 344-341â¯Ma. Sills of the JG were emplaced between c. 347 and c. 334â¯Ma. The composite KÅodzko-ZÅoty Stok Pluton, which includes the KZSG and accompanying mafic enclaves and pyroxenite and lamprophyre dykes, was mainly emplaced at 340-333â¯Ma. The magmas of the KZSG possibly facilitated the final amalgamation of the Sudetic counterparts of the Teplá-Barrandia and Saxothuringia microplates during the orogenic uplift of the latter. Petrologic and oxygen isotopic data further indicate partial post-magmatic hydrothermal and/or alteration processes. Our new data further stress the connection of magma transfer and active shear zones, which could manifest as crustal-scale magma-ascent conduits.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Lithos - Volumes 316â317, September 2018, Pages 385-405
Journal: Lithos - Volumes 316â317, September 2018, Pages 385-405
نویسندگان
MirosÅaw JastrzÄbski, Katarzyna Machowiak, Ewa KrzemiÅska, G. Lang Farmer, Alexander N. Larionov, Mentor Murtezi, JarosÅaw Majka, Sergey Sergeev, Edward M. Ripley, Martin Whitehouse,