《Zircon U-Pb dating and Lu-Hf isotope study of intermediate-mafic sub-volcanic and intrusive rocks in the Lishui Basin in the middle and lower reaches of Yangtze River.》.pdf

Chin．Sci．Bul1．(2014)59(27)：3427—3440 csb．scichina．com DoI10．1007，sl1434—0140358—7 www ．springer．com／scp Geology ZirconU-PbdatingandLu-Hfisotopestudyofintermediate-mafic sub．volcanicandintrusiverocksintheLishuiBasininthem iddle andlowerreachesofYangtzeRiver LijuanWang。JianpingHuang J‘inhaiYu。 W ．L．Griffin ‘RuchengW ang。ShaoqinZhang ‘ YingheYang Received：18December2013／Accepted：21February2014／Publishedonline：26April2014 @ ScienceChinaPressandSpringer—VerlagBerlinHeidelberg2014 Abstract EightMesozoicsub．volcallicandintrusiverocks continent．In themi ddle—lateJurassictoearly Cretaceous intheLishuiBasinhavebeenselectedforzirconU—pbdating f170-135Ma)，htePacificplatestartedtosubductbeneathhte and Lu．Hfisotopic naalysis．TheLaohutou．Datongshan． Eurasiancontinent，producingacompressivetectonicsetting， Daweizhuang，Yeshanao，Yanwaqiao，Xibeishan，Chang． nad magmatism progressedfrom coasttothe inlnad．Th e shantounadJinashanporphyritesyieldconcordantearlyCre． magmasofhtisperiod werederived mostly from partial taceousagesof130．5士 1．6Ma．136．0士 3．4Ma．132．7士 meltingofnacientcrest．After ～135Ma．hte subduction 2．7Ma，127．0士 1．9Ma，129．4士 1．7Ma，133．2士 2．1Ma， weakened，andtherollbackofthesubductedPacificplate 131．1土 2．3Manad 127．4士 1．8Ma．respectively．Zircon producedanextensionalenvrionment．Thisledtohteforma— 8}Ⅱ(valuesofrtheserocksrangefrom-3．54t0—9．11，mostly tionofvolcanicbasins，thepartialmeltingofenrichedmantle between-3．54and-5．93．suggestingsourcessimilartohtose sourcesnadlessnacientcrust，na dtheintrusionofvolumi nous forcoevaligneousrocksinohtervolcanicbasinsalongthe intermediate．maficigneousrocks． middlenadlowerreachesofYangtzeRiver．Co