کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5785755 | 1640181 | 2017 | 31 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Determining age of Pan African metamorphism using Sm-Nd garnet-whole rock geochronology and phase equilibria modeling in the Tasriwine ophiolite, Sirwa, Anti-Atlas Morocco
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Determining age of Pan African metamorphism using Sm-Nd garnet-whole rock geochronology and phase equilibria modeling in the Tasriwine ophiolite, Sirwa, Anti-Atlas Morocco Determining age of Pan African metamorphism using Sm-Nd garnet-whole rock geochronology and phase equilibria modeling in the Tasriwine ophiolite, Sirwa, Anti-Atlas Morocco](/preview/png/5785755.png)
چکیده انگلیسی
Sm-Nd garnet-whole rock geochronology and phase equilibria modeling have been used to determine the age and conditions of regional metamorphism within the Tasriwine ophiolite complex, Sirwa, Morocco. Pressure and temperature estimates obtained using a NaCaKFMASHT phase diagram (pseudosection) and garnet core and rim compositions predict that garnet growth began at â¼0.72 GPa and â¼615 °C and ended at â¼0.8 GPa and â¼640 °C. A bulk garnet Sm-Nd age of 647.2 ± 1.7 Ma, calculated from a four point isochron that combines whole rock, garnet full dissolution and two successively more aggressive partial dissolutions, provides a precise date for garnet formation and regional metamorphism. The age is over 15 million years younger than a previous age estimate of regional metamorphism of 663 ± 13 Ma based upon a SHRIMP U-Pb date from rims on zircon from the Iriri migmatite. The new data provide further constraints on the age and nature of regional metamorphism in the Anti-Atlas mountains and emphasizes that garnet growth during regional metamorphism may not necessarily coincide with magmatism/anatexis which predominate the signature witnessed by previous U-Pb studies. The ability to couple PT estimates for garnet formation with high precision Sm-Nd geochronology highlights the utility of garnet studies for uncovering the detailed metamorphic history of the Anti-Atlas mountain belt.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of African Earth Sciences - Volume 127, March 2017, Pages 88-98
Journal: Journal of African Earth Sciences - Volume 127, March 2017, Pages 88-98
نویسندگان
Jeremy D. Inglis, Kevin Hefferan, Scott D. Samson, Hassan Admou, Ali Saquaque,