地质通报2017，Vol.36Issue(5)：726-737,12.
云开地区早古生代竹雅-石板辉长岩锆石U-Pb定年与Lu-Hf同位素特征
Geochronology and Lu-Hf isotope of Early Paleozoic Zhuya-Shiban gabbros in Yunkai terrane, South China
摘要
Abstract
Early Paleozoic mafic intrusive rocks in Yunkai terrane commonly occur as small stocks that intruded into pre-Cambrian strata and/or contemporary gneissic granite, with main rock types being gabbro and norite gabbro. The gabbros in Zhuya and Yunlu yielded 206Pb/238U weighted age of ca. 445Ma. The gabbros show relatively high MgO, CaO, low TiO2 content, very low ∑REE (20.8×10-6~26.6×10-6), weak enrichment of LREE and strong depletion of HFSE (Nb-Zr-Ti-P). Zircons give negative εHf(t) and TDM model ages from 1.1Ga to 1.4Ga, showing the features of an enriched mantle source. Tectonic setting analysis shows that the gab?bors acted like volcanic arc rocks. Previous studies show many Early Paleozoic mafic rocks in Cathaysia Block with characteristic fin?gerprints of arc volcanic rock features, and hence the Early Paleozoic geotectonic evolution history in Yunkai terrane (even Cathaysia Block) should be reconsidered.关键词
辉长岩/弧火山岩/早古生代/锆石U-Pb定年/云开地区Key words
gabbro/arc volcanic rock/Early Paleozoic/zircon U-Pb dating/Yunkai terrane分类
天文与地球科学引用本文复制引用
周岱,龙文国,王磊,贾小辉..云开地区早古生代竹雅-石板辉长岩锆石U-Pb定年与Lu-Hf同位素特征[J].地质通报,2017,36(5):726-737,12.基金项目
中国地质调查局项目《信宜-增城-龙川构造混杂岩带研究》(编号:12120114039201)、《桂东-粤西成矿带云开-抱板地区地质矿产调查》(编号:121201009000150011)和国家自然科学基金项目《粤北罗岗钾玄质侵入岩的岩石成因及其动力学意义》(批准号:41302046) （编号:12120114039201）
