فرورانش دوسویه نامتقارن؛ نظریه جدید در مورد محیط تکتونوماگمایی و متالوژنی بلوک لوت، شرق ایران

نوع مقاله : علمی- پژوهشی

نویسندگان

1 فردوسی مشهد

2 آویرو

چکیده

زون‌های فرورانش به‌سمت غرب، برخلاف زون‌های فرورانش به‌سمت شرق ویژگیهای مشترکی شامل ساختارهای کم‌ارتفاع، دراز گودال عمیق، صفحه فرورونده پرشیب و حوضه پشت‌قوسی مرکب دارند. محیط تکتونوماگماتیسم و متالوژنی بلوک لوت در حال حاضر مورد بحث است و نظریات بسیاری مطرح شده اند. علی رغم اینکه برخی مساله فرورانش را مردود دانسته اند، اکثر محققین فرورانش را به زیر بلوک افغان در نظر گرفته اند، اما عده ای معتقدند که پوسته اقیانوسی به زیر بلوک لوت کشیده شده است. نهشته های مس - طلای پورفیری در محیط ژئوتکتونیکی جزایر قوسی، طی ائوسن میانی تشکیل شده اند، در حالی‌که نهشته های مولیبدن دار در ارتباط با ضخیم‌شدگی پوسته طی الیگوسن بوده اند. در این مقاله، داده های جدید عناصر کمیاب و ژئوشیمی ایزوتوپی گرانیتوئیدهای بلوک لوت همراه با شواهد ساختاری ارائه می شوند که نشان‌دهنده فرورانش دوسویه نامتقارن به زیر هر دو بلوک لوت و افغان با سرعت‌های متفاوت پوسته اقیانوسی می باشد.

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