کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4732954 1640491 2016 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Contrast in stress–strain history during exhumation between high- and ultrahigh-pressure metamorphic units in the Western Alps: Microboudinage analysis of piemontite in metacherts
ترجمه فارسی عنوان
کنتراست در تاریخ کشش تنش در هنگام خروج از واحدهای متامورف با فشار بالا و فوق العادهای در آلپ های غربی: تجزیه و تحلیل میکروبوادیناژ پگنتیت در متاکارتان
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی


• Five HP and one UHP samples of metachert were collected from the Western Alps.
• These samples of metachert contain microboudinage structures of piemontite.
• Stress analysis with the microboudinage structures was performed for the 6 samples.
• Estimated stress for the HP metacherts is higher than that for the UHP metachert.

Our analyses of microboudinage structures of piemontite grains embedded within six samples of metachert, one collected from an ultrahigh-pressure (UHP) metamorphic unit at Lago di Cignana in Italy of the Western Alps, and the other five from surrounding high-pressure (HP) metamorphic units in Italy and France, have revealed that the structures are all symmetrical in type, and were presumably produced in coaxial strain fields. Stress–strain analyses of the microboudinaged grains revealed significant contrasts in the stress and strain histories of the UHP and HP metamorphic units, with the differential stress recorded by the UHP sample being unequivocally lower than that recorded by the five HP samples. In addition, our analyses showed that the UHP sample underwent stress-relaxation during microboudinage, whereas the five HP samples did not. On the basis of these observations and analyses we discuss the mechanical decoupling of the UHP and HP units that led to different histories in differential stress between the units during exhumation of the Western Alps.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Structural Geology - Volume 89, August 2016, Pages 168–180
نویسندگان
, , , , ,