Skip navigation
  • 中文
  • English

DSpace CRIS

  • DSpace logo
  • Home
  • Organizations
  • Researchers
  • Research Outputs
  • Explore by
    • Organizations
    • Researchers
    • Research Outputs
  • Academic & Publications
  • Sign in
  • 中文
  • English
  1. NTU Scholars
  2. 理學院
  3. 地質科學系
Please use this identifier to cite or link to this item: https://scholars.lib.ntu.edu.tw/handle/123456789/431849
Title: Short episodes of crust generation during protracted accretionary processes: Evidence from Central Asian Orogenic Belt, NW China
Authors: Tang G.-J.
Chung S.-L.
Hawkesworth C.J.
Cawood P.A.
Wang Q.
Wyman D.A.
Xu Y.-G.
Zhao Z.-H.
SUN-LIN CHUNG 
Keywords: accretionary orogen;Central Asian orogenic belt;crustal generation;granites;North Xinjiang
Issue Date: 2017
Journal Volume: 464
Start page/Pages: 142-154
Source: Earth and Planetary Science Letters
Abstract: 
Accretionary orogens are major sites of generation of continental crust but the spatial and temporal distribution of crust generation within individual orogens remains poorly constrained. Paleozoic (?540¡V270 Ma) granitic rocks from the Alati, Junggar and Chinese Tianshan segments of the Central Asian Orogenic Belt (CAOB) have markedly bimodal age frequency distributions with peaks of ages at ?400 Ma and 280 Ma for the Altai segment, and ?430 Ma and 300 Ma for the Junggar and Chinese Tianshan segments. Most of the magma was generated in short time intervals (?20¡V40 Ma), and variations in magma volumes and in Nd¡VHf isotope ratios are taken to reflect variable rates of new crust generation within a long-lived convergent plate setting. The Junggar segment is characterized by high and uniform Nd¡VHf isotope ratios (£`Nd(t)=+5 to +8; zircon £`Hf(t)=+10 to +16) and it appears to have formed in an intra-oceanic arc system. In the Altai and Chinese Tianshan segments, the Nd¡VHf isotope ratios (£`Nd(t)=?7 to +8; zircon £`Hf(t)=?16 to +16) are lower, although they increase with decreasing age of the rock units. The introduction of a juvenile component into the Chinese Tianshan and Altai granitic rocks appears to have occurred in continental arc settings and it reflects a progressive reduction in the contributions from old continental lower crust and lithospheric mantle. Within the long-lived convergent margin setting (over ?200 Ma), higher volumes of magma, and greater contributions of juvenile material, were typically emplaced over short time intervals of ?20¡V40 Ma. These intervals were associated with higher Nb/La ratios, coupled with lower La/Yb ratios, in both the mafic and granitic rocks, and these episodes of increased magmatism from intraplate-like sources are therefore thought to have been in response to lithospheric extension. The trace element and Nd¡VHf isotope data, in combination with estimates of granitic magma volumes, highlight that crust generation rates are strongly non-uniform within long-lived accretionary orogens. The estimated crust generation rates range from ?0.1 to ?40 km3/km/Ma for the Paleozoic record of the CAOB, and only comparatively short (20¡V40 Ma) periods of elevated magmatic activity had rates similar to those for modern intra-oceanic and continental arcs. ? 2017 Elsevier B.V.
URI: https://scholars.lib.ntu.edu.tw/handle/123456789/431849
ISSN: 0012821X
DOI: 10.1016/j.epsl.2017.02.022
Appears in Collections:地質科學系

Show full item record

SCOPUSTM   
Citations

96
checked on Feb 27, 2023

WEB OF SCIENCETM
Citations

86
checked on Mar 12, 2023

Page view(s)

32
checked on Mar 23, 2023

Google ScholarTM

Check

Altmetric

Altmetric

Related Items in TAIR


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

臺大位居世界頂尖大學之列,為永久珍藏及向國際展現本校豐碩的研究成果及學術能量,圖書館整合機構典藏(NTUR)與學術庫(AH)不同功能平台,成為臺大學術典藏NTU scholars。期能整合研究能量、促進交流合作、保存學術產出、推廣研究成果。

To permanently archive and promote researcher profiles and scholarly works, Library integrates the services of “NTU Repository” with “Academic Hub” to form NTU Scholars.

總館學科館員 (Main Library)
醫學圖書館學科館員 (Medical Library)
社會科學院辜振甫紀念圖書館學科館員 (Social Sciences Library)

開放取用是從使用者角度提升資訊取用性的社會運動,應用在學術研究上是透過將研究著作公開供使用者自由取閱,以促進學術傳播及因應期刊訂購費用逐年攀升。同時可加速研究發展、提升研究影響力,NTU Scholars即為本校的開放取用典藏(OA Archive)平台。(點選深入了解OA)

  • 請確認所上傳的全文是原創的內容,若該文件包含部分內容的版權非匯入者所有,或由第三方贊助與合作完成,請確認該版權所有者及第三方同意提供此授權。
    Please represent that the submission is your original work, and that you have the right to grant the rights to upload.
  • 若欲上傳已出版的全文電子檔,可使用Sherpa Romeo網站查詢,以確認出版單位之版權政策。
    Please use Sherpa Romeo to find a summary of permissions that are normally given as part of each publisher's copyright transfer agreement.
  • 網站簡介 (Quickstart Guide)
  • 使用手冊 (Instruction Manual)
  • 線上預約服務 (Booking Service)
  • 方案一:臺灣大學計算機中心帳號登入
    (With C&INC Email Account)
  • 方案二:ORCID帳號登入 (With ORCID)
  • 方案一:定期更新ORCID者,以ID匯入 (Search for identifier (ORCID))
  • 方案二:自行建檔 (Default mode Submission)
  • 方案三:學科館員協助匯入 (Email worklist to subject librarians)
Build with DSpace-CRIS - Extension maintained and optimized by Logo 4SCIENCE Feedback