Ultrahigh-pressure metamorphic records hidden in zircons from amphibolites in Sulu Terrane, eastern China

Fulai Liu, Zeming Zhang, Ikuo Katayama, Zhiqin Xu, Shigenori Maruyama

    Research output: Contribution to journalArticle

    30 Citations (Scopus)

    Abstract

    The amphibolites occur sporadically as thin layers and blocks throughout the Sulu Terrane, eastern China. All analyzed amphibolite from outcrop and drill cores from prepilot drill hole CCSD-PP1 and CCSD-PP2, Chinese Continental Scientific Drilling Project in the Sulu Terrane, are retrograded eclogites overprinted by amphibolite-facies retrograde metamorphism, with characteristic mineral assemblages of amphibole + plagioclase + epidote ± quartz ± biotite ± ilmenite ± titanite. However, coesite and coesite-bearing ultrahigh-pressure (UHP) mineral assemblages are identified by Raman spectroscopy and electron microprobe analysis as inclusions in zircons separated from these amphibolites. In general, coesite and other UHP mineral inclusions are preserved in the cores and mantles of zircons, whereas quartz inclusions occur in the rims of the same zircons. The UHP mineral assemblages consist mainly of coesite + garnet + omphacite + rutile, coesite + garnet + omphacite, coesite + garnet + omphacite + phengite + rutile ÷ apatite, coesite + omphacite + rutile and coesite + magnesite. Compositions of analyzed mineral inclusions are very similar to those of matrix minerals from Sulu eclogites. These UHP mineral inclusion assemblages yield temperatures of 631-780°C and pressures of ≥2.8 × 103 MPa, representing the P-T conditions of peak metamorphism of these rocks, which are consistent with those (T = 642-726°C; P ≥ 2.8 × 103 MPa) deduced from adjacent eclogites. These data indicate that the amphibolites are the retrogressive products of UHP eclogites.

    Original languageEnglish
    Pages (from-to)256-267
    Number of pages12
    JournalIsland Arc
    Volume12
    Issue number3
    DOIs
    Publication statusPublished - Sep 1 2003

    Keywords

    • Amphibolite
    • Cathodoluminescene image
    • Laser Raman
    • Outcrops and core samples
    • Sulu Terrane
    • Ultrahigh-pressure mineral inclusio
    • Zircon

    ASJC Scopus subject areas

    • Geology

    Fingerprint Dive into the research topics of 'Ultrahigh-pressure metamorphic records hidden in zircons from amphibolites in Sulu Terrane, eastern China'. Together they form a unique fingerprint.

  • Cite this