کانی‌‌شناسی، دما- فشارسنجی و تفسیر جایگاه زمین‌ساختی گنیس‌های غرب سلطان‌آباد (شمال‌شرق سبزوار)

نویسندگان

1 دانشگاه تربیت معلم

2 دانشگاه بین المللی امام خمینی

چکیده

منطقه­ی مورد بررسی در شمال­شرق سبزوار (استان خراسان رضوی) و در غرب سلطان­آباد واقع است. در این منطقه یک مجموعه دگرگونی شامل سنگ­های رخساره­ی­ شیست سبز، شیست آبی، آمفیبولیت و اکلوژیت (؟) برونزد دارند. توده­ی گنیسی در بخش میانی این مجموعه (کوه چیلی) قرار دارد. تغییراتی از لحاظ پروتولیت و شدت برگوارگی در این توده وجود دارد. شواهد صحرایی، ژئوشیمی سنگ، داده­های سال سنجی و شرایط فشار دگرگونی تقریبا مشابه گنیس­ها با شیست­های آبی (گنیس: Kb 9/10 P = و شیست­ آبی: Kb 14- 11 P =) بیانگر آن است که پروتولیت گنیس­ها، سری­های تفریق یافته از پوسته­ی اقیانوسی هستند که با حرکت رو به شمال خرده قاره­ی ایران مرکزی همراه با سری­های مافیک حوضه­ی اقیانوسی سبزوار (شیست­های آبی) دستخوش دگرگونی زون فرورانش در ائوسن بالایی شده­اند.

کلیدواژه‌ها


عنوان مقاله [English]

Mineralogy, thermobarometry and tectonic setting interpretation of gneisses from western Soltan Abad (NE Sabzevar)

چکیده [English]

The study area is situated in the west of Soltan Abad prom NE Sabzevar (Razavi Khorasan province). There is an exposure of metamorphic complex that contains greenschist, blueschist, amphibolite and eclogite (?) facieses rocks. Gneissic body is located in the middle part of this complex (Koh-e-Chili). Protolith and foliation intensity are variable in this body. Field evidences, whole rock geochemistry, geochronological data and nearly the same metamorphic pressure conditions of gneisses and blue schists (Gneiss: P = 10.9 Kb and Blueschist: P = 11-14 Kb) indicate that protolith of the gneisses have been differentiated series of oceanic crust and have experienced subduction zone metamorphism along with mafic series of Sabzevar oceanic basin (blueschists) as a consequence of north-ward movement of central Iranian microcontinent in the Upper Eocene.

کلیدواژه‌ها [English]

  • Thermobarometry
  • gneiss
  • blueschist
  • Soltan Abad
  • Sabzevar
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