بررسی منشأ و شرایط شکل‌‌ گیری آگات‌ ها‌ی خور و بیابانک (استان اصفهان)

زمین شناسی اقتصادی

مقاله 4، دوره 6، شماره 2 - شماره پیاپی 11، دی 1393، صفحه 277-289   

نوع مقاله: علمی- پژوهشی

شناسه دیجیتال (DOI): 10.22067/econg.v6i2.44778

نویسندگان

فروغ ملک محمودی^{* 1}؛ محمود خلیلی²

¹شهرکرد

²اصفهان

چکیده

آگات‌های خور و بیابانک در حفرات گدازه‌های آتشفشانی ائوسن با ترکیب بازالت آندزیتی و در دل افق بنتونیتی خور شکل گرفته‌اند. مشاهدات صحرایی حاکی از فراوانی این ترکیبات سیلیسی در مجاورت درزه‌ها و گسلهاست. بر اساس آنالیز XRD ترکیبات پرکننده‌ حفرات در منطقه‌ مورد مطالعه علاوه بر آگات شامل عناصر کلسیت، دولومیت و باریت است. مقایسه‌ عناصر نادر و نادر خاکی در نمونه‌های سیلیسی با سنگ میزبان آندزیتی بیانگر روندی مشابه به همراه تهی‌شدگی شدید در نمونه‌های سیلیسی است. شواهد کانی‌شناسی حاکی از آن است که ژئودهای منطقه‌ طشتاب خور بر اثر خروج متناوب سیالات گرمابی در دمای پایین شکل گرفته‌اند. مطالعات ایزوتوپ‌های پایدار اکسیژن و دوتریوم نشان می‌دهد سیالات پدید‌ آورنده‌ این ترکیبات سیلیسی دارای منشأ جوی هستند.

کلیدواژه‌ها

آگات؛ سیالات گرمابی؛ ایزوتوپ پایدار؛ خور؛ ایران مرکزی

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