سنگ شناسی و ژئوشیمی گدازه های بالشی محدوده هرسین، افیولیت کرمانشاه، باختر ایران

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانشکده علوم‌زمین، دانشگاه شهید بهشتی، تهران، ایران

2 پژوهشکده علوم‌زمین، سازمان زمین‌شناسی و اکتشافات معدنی کشور، تهران، ایران

چکیده

توالی خروجی مجموعه افیولیتی هرسین به صورت گدازه­های بالشی بازالتی در حوالی روستای تمرک و گردنه گشور در خاور هرسین و کرمانشاه، در باختر ایران برونزد دارند. گدازه­های بالشی رخنمون یافته در امتداد گسل اصلی زاگرس بخشی از زمین‌درز افیولیتی بین کمربند زاگرس و زون سنندج- سیرجان به شمار می‌آیند. این سنگ­ها در حوالی روستای تمرک دارای ترکیب بازالت تا بازالت آندزیتی و در گردنه گشور ترکیبی در حد تراکی آندزیت بازالتی را دارند. از نظر سرشت ماگمایی سنگ­های محدوده تمرک در قلمرو نیمه قلیایی و سنگ­های گردنه گشور در محدوده قلیایی واقع می­شوند و از نظر محیط زمین‌ساختی- ماگمایی، گدازه­های بالشی تمرک به محیط E-MORB و گدازه­های بالشی گشور به  بازالت­های WPB تعلق دارند. این بازالت­ها در هر دو منطقه تمرک و گشور از گوشته منتج شده و از LILE ،LREE و برخی از عناصر HFSE غنی شده هستند. این سنگ­ها بقایایی از سنگ‌کره اقیانوسی نئوتتیس­ هستند که بین دو حاشیه قاره­ای عربستان و اوراسیا تشکیل شده­اند.

کلیدواژه‌ها


عنوان مقاله [English]

Petrology and Geochemistry of the Extrusive Sequence of Harsin Ophiolite, W Iran

نویسندگان [English]

  • Kh. Allahyari 1
  • M. Pourmoafi 1
  • M. Khaleatbari-Jafari 2
1 Earth Science Faculty, Shahid Beheshti University, Tehran, Iran
2 Research Institute for Earth Science, Geological Survey of Iran, Tehran, Iran
چکیده [English]

The extrusive sequence of Kermanshah ophiolite complex are exposed in Tamark and Gashor area, in east of Kermanshah and Harsin, in west of Iran. These lavas are located along the Main Zagros Reverse Fault, which marks the ophiolitic suture zone between the Zagros belt and the Sanandaj-Sirjan zone. These rocks with pillow structures are nominated in Tamark area as basalt to basaltic andesite and in Gashor area as basalt to basaltic trachy-andesite. According to classifications for magmatic series Tamark’s pillows are belong to subalkali series and Gashor’s pillows are belong to alkaline series. In classifications of tectono magmatic patterns, Tamark and Gashor’s basalts respectively are plotted in E-MORB and WPB. These rocks in both of pillows enriched from LILE, LREE and some HFSE and the enriched mantel is the source of the primitive magma. They represent the Neo-Tethyan oceanic lithosphere originally existing between the Arabian and Eurasian continental margins.

کلیدواژه‌ها [English]

  • Pillow lavas
  • Harsin ophiolite
  • Zagros Belt
  • Neotethys
آقانباتی، ع.، 1367- نقشه زمین‌شناسی با مقیاس 1:250.000 کرمانشاه. سازمان زمین‌شناسی و اکتشافات معدنی کشور.
شهیدی، ع.، نظری، ح.، 1376- نقشه زمین‌شناسی با مقیاس 1:100.000 هرسین. سازمان زمین‌شناسی و اکتشافات معدنی کشور.
 
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