ژئوشیمی و پتروژنز سری‌های بازالتی-آندزیتی افیولیت‌های سیه‌چشمه، شمال باختر خوی

نوع مقاله: مقاله پژوهشی

نویسندگان

1 بخش زمین‌شناسی، دانشگاه پیام نور خوی، خوی، ایران

2 دانشکده علوم زمین، دانشگاه شهید بهشتی، تهران، ایران

3 دانشکده علوم زمین، دانشگاه دامغان، دامغان، ایران

چکیده

مجموعه افیولیتی سیه چشمه ادامه بخش شمال- شمال باختری افیولیت‌های خوی است که شامل واحدهای دگرگونی، توالی گوشته‌ای، گدازه‌های بازالتی و آندزیتی به همراه سنگ‌آهک‌های پلاژیک و چرت‌های کرتاسه بالایی هستند. گدازه‌های بازالتی-آندزیتی این مجموعه افیولیتی را می‌توان به دو دسته گدازه‌های قلیایی و گدازه‌های کلسیمی- قلیایی تقسیم‌بندی کرد. وجود منشورهایی از آمفیبول‌های غنی از تیتان به‌همراه کلینوپیروکسن‌های تیتان‌دار خاص گدازه‌های قلیایی موجود در افیولیت‌های سیه‌چشمه است. گدازه‌های کلسیمی- قلیایی با غنی‌شدگی در LREE و تهی‌شدگی در HFSE و گدازه‌های قلیایی با غنی‌شدگی در LREE و HFSE مشخص می‌شوند. واکنش یک پلوم گوشته‌ای با پشته میان اقیانوسی می‌تواند برای منشأ بازالت‌های قلیایی در نظر گرفته  شود در حالی‌که عملکرد یک زون فرورانش می‌تواند مسئول پیدایش بازالت های کلسیمی- قلیایی باشد.

کلیدواژه‌ها


عنوان مقاله [English]

Geochemistry and Petrogenesis of Andesitic-Basaltic Series in Siah-Cheshmeh Ophiolite, NW of Khoy

نویسندگان [English]

  • M. Poormohsen 1
  • M. Rahgoshay 2
  • I. Azadi 2
  • H. Shafaii Moghadam 3
1 Department of Geology, Peyam-e-Noor University of Khoy, Khoy, Iran
2 Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran
3 Fculty of Earth Sciences, Damghan University, Damghan, Iran
چکیده [English]

The Siah-Cheshmeh ophiolites at the north-northwest part of the Khoy ophiolites show a dismembered pile of metamorphic units, mantle sequence, and basaltic-andesitic lavas associated with Late Cretaceous pelagic limestones and cherts.  The basaltic-andesitic lavas can be divided into alkaline and calc-alkaline varieties. The presence of Ti-rich amphibole prisms and Ti-bearing clinopyroxenes is characteristic of these lavas. The calc-alkaline lavas are characterized by enrichment in LREE and depletion in HFSE while the alkaline lavas display positive LREE and HFSE anomalies. The interaction between mantle plumes with a spreading center can be considered for generation of alkaline basalts while a subduction zone is responsible for the genesis of calc-alkaline basalts.

کلیدواژه‌ها [English]

  • Siah-Cheshmeh ophiolite
  • Alkaline basalts
  • Calc-alkaline basalts
  • Mantle plume
  • Subduction zone
کتابنگاری
نقشه زمین‌شناسی 1:250000 چهار گوش ماکو، سازمان زمین‌شناسی واکتشافات معدنی کشور.
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