کاربرد کانی‌های سنگین در تفسیر خاستگاه رسوب‌های آواری فلات قاره‌ی دریای عمان- ناحیه چابهار تا جاسک

نویسندگان

1 دانشگاه فردوسی مشهد

2 مرکز ملی اقیانوس‌شناسی ایران

چکیده

هدف از این بررسی، شناسایی کانی­های سنگین در رسوب­های دریائی فلات قاره دریای عمان و بکارگیری آن­ها در تفسیر خاستگاه آن­ها است. هفت نمونه از یک مغزه از کف دریا و سه نمونه از رسوب­های پهنه­های جزر و مدی برای این کار انتخاب شدند. برای جداسازی کانی­های سنگین از محلول بروموفورم و نیز شناسایی آن­ها از میکروسکوپ بینوکولار و آنالیز SEM مجهز به EDS استفاده شد. مهم­ترین کانی­های سنگین نمونه­های مورد بررسی عبارتند از زیرکن، آپاتیت، هورنبلند، گارنت، تورمالین، روتیل، ایلمینیت و باریت. فراوانی بالای زیرکن، آپاتیت و تورمالین مؤید وجود سنگ­های آذرین فلسیک در خاستگاه است. با توجه به سنگ­های آتشفشانی مناطق فرورانش می­توان سری تولئیتی کوارتزدار در کمان­های جوان و حوضه­های پشت کمانی را به­عنوان خاستگاه اصلی این رسوب­ها در نظر گرفت. حضور هورنبلند در نمونه­ها نیز نشان دهنده­ی بالاآمدگی زمین­ساختی و تشکیل افیولیت در منطقه است.

کلیدواژه‌ها


عنوان مقاله [English]

Application of heavy minerals in Provenance interpretation of siliciclastics in Oman continental shelf, Chabahar to Jask area

چکیده [English]

Recognition of heavy minerals in Oman continental shelf sediments and their application for interpretation of sediments sourc rock is the purpose of this study. Seven core samples of sea sediment and three surface samples from tidal flat area have been examined. Heavy minerals are dense grains, wich are found not only in rocks, but also in different types of sand and sediments. Separation of heavy minerals was conducted by heavy liquid of bromoform. Separated heavy minerals were studied by using binocular microscope and SEM equipped with EDS analyser. Various heavy minerals of zircon, garnet, tourmaline, routil, barite, apatite, hornblende, iliminite and magnetite were recognized in studied sediment. The high abundance of zircon, apatite and tourmaline in sediments indicates the felsic rocks as origin. Hornblende was eroded from ophiolitie in ubducted zones. The quartz–toleitic rocks are likely to be the main source for sediments, which are common in back arc zone of Makran subduction

کلیدواژه‌ها [English]

  • heavy mineral
  • source rock
  • horonblende
  • Zircon
  • apatite
  • tourmaline
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