中生代华北南缘带状岩石圈结构特征及其大陆形成演化意义

Translated title of the contribution: Mesozoic zonal lithosphere beneath the southern margin of the North China: significance for continental formation and evolution

Jian Ping Zheng*, Chun Mei Yu, Yu Ping Su, Hua Yun Tang, Qi Rong Wei, Zhi Hai Zhang, Feng Xiang Lu

*Corresponding author for this work

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The formation and destruction of the continental root is one of the most important going topics on the solid earth sciences. A series of deep-seated xenoliths, including mafic to felsic granulite, eclogite, metagabbro, pyroxenite and peridotite, from the Xinyang area with unique temporal and spatial meaning, at southern margin of the North China, were used to dating in ages and properties. The geometrical model of the zonal lithosphere structure in age and composition were suggested for the conjoint position of multi-blocks in Mesozoic (~160 Ma). Basing on the zonal lithosphere, the authors also discussed the dynamic processes for its formation. The exposed rocks up to ca. 2.85 Ga old are underlain by felsic granulites and rare pyroxenites with zircon ages of 3.6-3.4 Ga (to ca. 30 km depth). Deeper (ca. 30-45 km) parts of the lower crust consist of high-pressure mafic to felsic granulite and meta-gabbro, which give Paleoproterozoic (2.0-1.8 Ga) zircon ages. Our data show the significance of underplating and vertical crustal growth in the Paleoproterozoic, which was related to the amalgamation of the eastern and western block of this craton and a global (Columbia) supercontinent assembly. Hf-isotope data indicate that both juvenile material and remelting of older (3.8-3.0 Ga) crustal rocks were involved in this important event. Paleozoic (440-260 Ma) and Early Mesozoic (228-219 Ma) zircons are also found in xenoliths from the deeper part of the lower crust and the uppermost mantle (i.e., eclogite and peridotite). They are interpreted as reflecting geodynamic processes related to the continental collision between this craton and the Yangtze craton, respectively. The xenoliths from Xinyang diatremes thus record the growth and modification of the old (Paleo-Mesoarchean?) continental lithosphere by magma underplating during several tectonic events: assembly of the southern and northern parts of the Eastern Block in Neoarchean time, collision of the western and eastern blocks along the Trans-China orogen in the Paleoproterozoic, and subduction and collision of the Yangtze craton with the North China craton in early Paleozoic and Triassic times, respectively.

Original languageChinese
Pages (from-to)28-36
Number of pages9
JournalDiqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences
Volume34
Issue number1
Publication statusPublished - Jan 2009
Externally publishedYes

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Keywords

  • Continental formation and evolution
  • Deep-seated xenolith
  • Dynamic mechanism
  • Mesozoic
  • Southern margin of the North China
  • Zonal lithosphere

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