中文摘要：

巴家滩岩体是下扬子庐枞火山盆地内的重要岩体之一。野外调查发现,巴家滩岩体有两期岩浆活动形成,细粒石英正长岩脉贯穿于中粗粒辉石二长岩之中。分别对辉石二长岩和石英正长岩开展了LA-ICPMS锆石U-Pb定年,结果分别为133.2Ma±1.2Ma和130.1Ma±1.7 Ma,分别对应了砖桥组喷发旋回和双庙组喷发旋回。庐枞盆地火山岩从早期至晚期,岩浆有向富碱演化的趋势,而巴家滩岩体两期岩浆的精确定年和岩石学特征指示其岩浆演化趋势和火山岩一致,表现为次火山岩的特征。庐枞地区中生代侵入岩可以划分为三期：134Ma～132Ma,131Ma～128Ma和127Ma～124Ma。

英文摘要：

Bajiatan pluton is one of the important intrusive rocks in Luzong volcanic basin.During field investigation,two stages of magmatism,characterized by fine grained quartz syenite dike intruded into medium-coarse grained pyroxene monzonite,have been recognized.Zircons from the pyroxene monzonite and quartz syenite are selected to perform LA-ICPMS dating and yielded the ages of 133.2Ma±1.2 Ma and 130.1 Ma±1.7 Ma,respectively,corresponding to the eruption period of Zuanqiao and Shuangmiao Formations.The volcanic rocks in Luzong basin have alkalineenriched trend from early to later stages and is consistent with two stages of magmatism of the Bajiatan pluton,showing a subvolcanic rock character.The Mesozoic intrusive rocks in Luzong area can be divided into three stages,134Ma～132Ma,131Ma～128Ma and 127Ma～124Ma.