Zircon Hf isotope of Yingfeng Rapakivi granites from the Quanji Massif and ~2.7 Ga crustal growth

Nengsong CHEN*, Songlin GONG, Xiaoping XIA, Hongyan GENG, Lu WANG, Min SUN, Timothy M. KUSKY

*Corresponding author for this work

Research output: Journal PublicationsJournal Article (refereed)

23 Citations (Scopus)

Abstract

The Quanji (Chinese Source) Massif is located in the Northwest China, which is interpreted as a micro-continent that is composed of metamorphic basement and stable cover strata. There are some controversies of genetic relationship between the Quanji Massif and the major cratons in China. In this study, we obtained in situ zircon U-Pb and Hf isotopic compositions of the Yingfeng (Chinese Source) rapakivi granites from the northwest Quanji Massif by application of LA-MC-ICP-MS technique. Twenty U-Pb age measurements points are concordant or near concordant, and their weighted mean 207Pb/206Pb age is 1 793. 9±6. 4 Ma (MSWD= 1. 09), yields an upper intercept age of 1 800±17 Ma (MSWD=0. 41); 19 Hf isotope measurements yield a two-stage Hf model ages (TDM2) of 2. 63 to 2. 81 Ga, with a weighted average age of about 2. 70±0. 02 Ga and e{open}Hf(t) values variate between -8. 91 to -5. 35. This indicates that magma source of the Yingfeng rapakivi granites were produced from partial melting of late stage of Neoarchean juvenile crust, and suggests a significant crustal growth event occurred in the Quanji Massif at that time. The Quanji Massif might be an ancient continental segment detached from the Tarim Craton based on the crustal growth history and other geological records. The Tarim Craton (including the Quanji Massif) and the North China Craton had a similar or homological early crustal evolution around ~2. 7 Ga, which implies that Tarim Craton might be one of the component parts of North China Craton.

Original languageEnglish
Pages (from-to)29-41
Number of pages13
JournalJournal of Earth Science
Volume24
Issue number1
DOIs
Publication statusPublished - Feb 2013
Externally publishedYes

    Fingerprint

Keywords

  • crustal growth
  • Quanji Massif
  • rapakivi granite
  • Tarim-North China Craton
  • tectonic evolution
  • zircon Hf isotope

Cite this