کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4731223 1640402 2013 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Diverse mineral compositions, textures, and metamorphic P–T conditions of the glaucophane-bearing rocks in the Tamayen mélange, Yuli belt, eastern Taiwan
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
پیش نمایش صفحه اول مقاله
Diverse mineral compositions, textures, and metamorphic P–T conditions of the glaucophane-bearing rocks in the Tamayen mélange, Yuli belt, eastern Taiwan
چکیده انگلیسی

This paper presents new petrologic data for high-pressure, low-temperature (HP–LT) metamorphic rocks at Juisui. We reinterpret the so-called “Tamayen block” (Yang and Wang, 1985) or “Juisui block” (Liou, 1981 and Beyssac et al., 2008) as a tectonic mélange. It is not a coherent sheet but rather a mixture dominated by greenschist and pelitic schist with pods of serpentinite, epidote amphibolite, and rare blueschist. Four types of glaucophane-bearing rocks are newly recognized in this mélange. Type I is in contact with greenschist lacking glaucophane and garnet. Glaucophane is present only as rare inclusions within pargasite. This type records metamorphic evolution from epidote blueschists-, epidote amphibolite-, to greenschist-facies. Type II contains characteristic zoned amphiboles from barroisite core to Mg-katophorite mantle and glaucophane rim, implying an epidote amphibolite-facies stage overprinted by an epidote blueschists-facies one. Type III includes winchite and indicates P–T conditions of about 6–8 kbar, approaching 400 °C. Type IV contains paragonite but lacks garnet; amphibole shows a Na–Ca core surrounded by a glaucophane rim. This type shows a high-pressure (?) epidote amphibolite-facies stage overprinted by an epidote blueschists-facies one. Amphibole zoning trends and mineral assemblages imply contradictory P–T paths for the four types of glaucophane-bearing rocks—consistent with the nature of a tectonic mélange. The new P–T constraints and petrologic findings differ from previous studies ( Liou et al., 1975 and Beyssac et al., 2008).


► This study provides new characterization of constituent minerals in Tamayen.
► We identified four types of glaucophane-bearing rocks.
► The amphiboles show diverse textures and complex zoning trends.
► The studied rocks were subjected to at least two different P–T paths.
► We reinterpret the so-called Tamayen “block” as a tectonic mélange.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Asian Earth Sciences - Volume 63, 15 February 2013, Pages 218–233
نویسندگان
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