رشد دنباله‌ای همزمان با دگرشکلی طی دگرگونی مجاورتی ناحیه‌ای فشار کم – دمای بالای منطقه قنداب، فریمان، شمال شرقی ایران

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشگاه فردوسی مشهد

چکیده

در این پژوهش، ویژگی های ریزساختاری سنگ­های مجموعه دگرگونی قنداب به عنوان یکی از مهم­ترین دگرگونی­های مجاورتی ناحیه­ای فشار کم - دمای بالای مطالعه شده در ایران بررسی شده است. شواهد بافتی معرف رشد دنباله­ای کانی­ها با افزایش درجه دگرگونی و در طول گسترش چین­خوردگی - برگوارگی است. ترتیب رشد دنباله­ای کانی­ها به صورت کوردیریت، آندالوزیت، گارنت و سیلیمانیت پیشنهاد شده است. برگوارگی اولیه(S1)  عموماً به صورت الگوی میانبارها در شکفته بلورهای کوردیوریت حفظ گردیده است. با این وجود، رشد شکفته­بلورهای آندالوزیت و گارنت همزمان با دگرشکلی و طی کسترش برگوارگی کنگره­ای (S2) صورت گرفته است. بر اساس شواهد بافتی گسترش سیلیمانیت در مراحل نهایی دگرگونی و دگرشکلی صورت گرفته است.     

کلیدواژه‌ها

عنوان مقاله [English]

Sequential syndeformational porphyroblast growth during low-pressure/high temperature contact regional metamorphism in the Ghandab region, NE Iran

نویسندگان [English]

  • Seyed Masoud Homam
  • Fereshteh Ranjbar Moghadam
Ferdowsi University of Mashhad
چکیده [English]

Detailed microstructural analysis has been conducted in the Ghandab metamorphic Complex, which is one of the most important high temperature – low pressure regional contact metamorphism studied areas in Iran. Textural evidence suggests the sequence of growth of minerals with increasing metamorphic grade and during development of a crenulation foliation. The sequence of mineral growth is considered to be cordierite, andalusite, garnet, and sillimanite.  The first foliation (S1) is preserved largely as inclusion trails in cordierite porphyroblasts. However, garnet and andalusite porphyroblasts are syndeformation crystals and grow during development of crenulation-foliation of S2. According to textural evidence, sillimanite produced late in the thermal history of metamorphism and deformation

کلیدواژه‌ها [English]

  • Ghandab metamorphic complex
  • sequential growth
  • foliation
  • deformation

مراجع

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سابقه مقاله

  • تاریخ دریافت: 01 آبان 1396
  • تاریخ بازنگری: 08 دی 1396
  • تاریخ پذیرش: 18 بهمن 1396

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