کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4728008 1356413 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Late orogenic collapse and thermal doming in the northern Gondwana margin incorporated in the Variscan Chain: A case study from the Ozieri Metamorphic Complex, northern Sardinia, Italy
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Late orogenic collapse and thermal doming in the northern Gondwana margin incorporated in the Variscan Chain: A case study from the Ozieri Metamorphic Complex, northern Sardinia, Italy
چکیده انگلیسی
A branch of the South European Variscan chain is noticeably exposed in Sardinia. The early stage of collision between the Northern Gondwana margin and the Armorica Terrane Assemblage (ATA) generated syn-metamorphic folding and thrusting. The evidences of such deformation are well preserved in the nappe zone, a structural domain characterized by stacking of different tectonic units under metamorphism of Barrovian greenschist facies. A late, post-nappe, shortening, under retrograde metamorphic conditions, gave rise to wide, upright, N120-N160 trending antiforms that control the trend of the chain. The structural analysis of the Ozieri Metamorphic Complex (OMC) shows evidence of an important phase of late-Variscan extensional tectonics. Deformation results in, the formation of oppositely dipping, normal shear zones, which developed at upper and middle structural level along the limbs of major regional antiforms causing fabric reactivation, crustal thinning, and exhumation of the OMC core. Within the OMC, the activity of the shear zones was coeval with HT-LP metamorphism as suggests the occurrence of syn-kinematic cordierite + andalusite ± sillimanite + biotite. Whereas syntectonic dykes and a tonalite body in the deeper part of the OMC indicate that early emplacement of melt along shear zones and/or in the antiform hinges possibly supplied the heat for the anomalous thermal gradient and triggered the exhumation of a core complex-like structure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Gondwana Research - Volume 13, Issue 3, April 2008, Pages 396-406
نویسندگان
, ,