Paleoproterozoic basement beneath the southern Jiangxi Province: Evidence from U-Pb ages and Lu-Hf isotopes in zircons from the Doushui lamprophyre

Jinhai Yu*, Lijuan Wang, S. Y. O'Reilly, Liangshu Shu, Tao Sun

*Corresponding author for this work

    Research output: Contribution to journalArticlepeer-review

    28 Citations (Scopus)

    Abstract

    This paper presents geochemical analyses of a lamprophyre intruding the Caledonian Doushui granite body in Shangyou County, southern Jiangxi Province. U-Pb dating and Hf-isotope analyses are especially carried out for zircons from it. Petrological and geochemical features show that the lamprophyre belongs to a high-K, weakly alkaline pyroxene-biotite lamprophyre. It is characterized by high Mg# (0.74), Ni (253 μg/g) and Cr (893 μg/g) contents, and also enriched in incompatible elements, such as REE, Rb, Sr, Ba and K. It is suggested that its primitive melt probably derived from enriched mantle metasomatized by non-crust-derived agent. Morphology and LAM-ICPMS dating results of zircons in the lamprophyre indicate that they are xenocrysts captured from deep crustal rocks. Most xenocrystic zircons formed at 1.86 Ga, and a few in different Phanerozoic periods. The Paleoproterozoic zircons are of magmatic origin and have similar 176Hf/177Hf and 176Lu/177Hf ratios, indicating that they probably are from the same igneous basement rock. The ages and Hf-isotope compositions of zircons from this basement rock are similar to those of Paleoproterozoic Danzhu granite in the southern Zhejiang Province, but extremely distinguished from the Nanling basement, suggesting that the study area probably is a westward extension part of Paleoproterozoic Wuyishan terrane in the eastern Cathaysia Block. These Paleoproterozoic zircons have low Hf-isotope compositions, characteristic of crustal source. Hf model ages of these zircons and the presence of older inherited cores within them, coupled with available other data reported by previous studies, suggest that the source of Paleoproterozoic magma is Neoarchaean crust, implying the existence of older basement in the Wuyishan terrane. U-Pb ages and Hf isotopes of five Phanerozoic zircons indicate that Paleoproterozoic basement underwent multi-reworking occurring in Caledonian, Indosinian and early Yanshanian, respectively. The Caledonian magmatism also involves reworking of juvenile crust.

    Original languageEnglish
    Pages (from-to)1555-1563
    Number of pages9
    JournalChinese Science Bulletin
    Volume54
    Issue number9
    DOIs
    Publication statusPublished - May 2009

    Fingerprint Dive into the research topics of 'Paleoproterozoic basement beneath the southern Jiangxi Province: Evidence from U-Pb ages and Lu-Hf isotopes in zircons from the Doushui lamprophyre'. Together they form a unique fingerprint.

    Cite this