Rb-Sr GEOCHRONOLOGY OF PEGMATITES, PLUTONIC ROCKS AND A HORNFELS IN THE REGION SOUTH-WEST OF ARAK, IRAN

نویسندگان: ثبت نشده
چکیده مقاله:

In the area SW of Arak, intrusives are emplaced into metasediments of early Mesozoic age. The intrusive rocks vary in morphology, structure and mineralogy, and exhibit various degrees of alterations; Rb-Sr geochronological data have been obtained to constrain their timing. There are three different groups of granitic rocks in the area: (a) the Astaneh intrusion, consisting of granite, biotite granite and granodiorite, intersected by abundant veins of quartz and aplite; (b) the Tavandasht-Gosheh intrusions, occurring as separate, small outcrops and (c) the Borujerd complex, composed of granitic intrusions with a wide range of late magmatic products including pegmatites and quartz veins, and with a well- developed aureole in pelitic country rocks. Rb-Sr data indicate that the first intrusive activity, which postdated low grade regional metamorphism, occurred during early Alpine tectonic movements, in lower Cretaceous times (about 120 Ma). A large elongate granitic intrusion (Older Granites), which occupies most of the Borujerd complex, and the first group of pegmatites (Older Pegmatites) were formed during this stage. Syntectonic intrusive activity associated with continuing Alpine movements, is represented by the Astaneh intrusion, emplaced at 99 Ma. Following this, a series of post-tectonic intrusions (Younger Granites) and pegmatitic veins (Younger pegmatites) were formed during the late Cretaceous-early Paleocene (70-52 Ma).

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

rb-sr geochronology of pegmatites, plutonic rocks and a hornfels in the region south-west of arak, iran

in the area sw of arak, intrusives are emplaced into metasediments of early mesozoic age. the intrusive rocks vary in morphology, structure and mineralogy, and exhibit various degrees of alterations; rb-sr geochronological data have been obtained to constrain their timing. there are three different groups of granitic rocks in the area: (a) the astaneh intrusion, consisting of granite, biotite g...

متن کامل

a swot analysis of the english program of a bilingual school in iran

با توجه به جایگاه زبان انگلیسی به عنوان زبانی بین المللی و با در نظر گرفتن این واقعیت که دولت ها و مسئولان آموزش و پرورش در سراسر جهان در حال حاضر احساس نیاز به ایجاد موقعیتی برای کودکان جهت یاد گیری زبان انگلیسی درسنین پایین در مدارس دو زبانه می کنند، تحقیق حاضر با استفاده از مدل swot (قوت ها، ضعف ها، فرصتها و تهدیدها) سعی در ارزیابی مدرسه ای دو زبانه در ایران را دارد. جهت انجام این تحقیق در م...

15 صفحه اول

the survey of the virtual higher education in iran and the ways of its development and improvement

این پژوهش با هدف "بررسی وضعیت موجود آموزش عالی مجازی در ایران و راههای توسعه و ارتقای آن " و با روش توصیفی-تحلیلی و پیمایشی صورت پذیرفته است. بررسی اسنادو مدارک موجود در زمینه آموزش مجازی نشان داد تعداد دانشجویان و مقاطع تحصیلی و رشته محل های دوره های الکترونیکی چندان مطلوب نبوده و از نظر کیفی نیز وضعیت شاخص خدمات آموزشی اساتید و وضعیت شبکه اینترنت در محیط آموزش مجازی نامطلوب است.

The field and microstructural study of Malayer plutonic rocks,west of Iran

A detail field and microscopic characteristics of Malayer Plutonic Rocks (162-187Ma), west of Iran, are discussed in details to evaluate relationships between deformation and pluton emplacement. The studied rocks were injected into the slate, phyllite and schists of so called "Hamadan phyllites and slates" in the Sanandaj-Sirjan zone. Studies have shown that there is a continuity from magmatic ...

متن کامل

on translation of politeness strategies in dialogues involving female characters in translations and retranslations of novels translated before and after the islamic revolution of iran and their effects on the image of women: a polysystem theory approach

abstract reception environment has considerable effects on accepting a translation. as the expectations of a target culture and its values and needs change throughout history, its criteria for accepting a translation or rejecting it will change accordingly (gentzler, 2001). the expectations of iran, as the reception environment in the present study, have changed after the islamic revolution. i...

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ذخیره در منابع من قبلا به منابع من ذحیره شده

{@ msg_add @}


عنوان ژورنال

دوره 13  شماره 3

صفحات  -

تاریخ انتشار 2002-09-01

با دنبال کردن یک ژورنال هنگامی که شماره جدید این ژورنال منتشر می شود به شما از طریق ایمیل اطلاع داده می شود.

کلمات کلیدی

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023