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豫西济源盆地位于秦岭造山带北部,是三叠纪-侏罗纪秦岭造山带的同造山盆地.对济源盆地中三叠世-中侏罗世6个组的碎屑锆石样品进行了LA-ICP-MS的U-Pb年龄分析.结果表明,碎屑锆石年龄主要分布于以下区间:2.9～1.7Ga、1.6～1.0Ga、1.0～0.8Ga、800～650Ma、520～380Ma、350～245Ma和～220Ma,其中除了2.9～1.7Ga的碎屑锆石主要来自于华北克拉通基底外,其他几个年龄段的锆石则主要来自于秦岭造山带,并且显示出随着地层年龄的逐渐变新,碎屑锆石年龄有逐渐变老的趋势.在中三叠世-晚三叠世早期样品中,主要年龄是350～245Ma,在晚三叠世晚期-中侏罗世早期样品中,1.6～1.0Ga、1.0～0.8Ga、800～650Ma和520～380Ma则逐渐增多,到了中侏罗世晚期,1.6～1.0Ga和520～380Ma依然存在于样品中,并且还发现了～220Ma年龄.碎屑锆石年龄结构指示了秦岭造山带印支期经历了由年轻的盖层到较老的基底的去顶过程.并与合肥、黄石盆地的碎屑锆石数据对比发现,早侏罗世时,去顶强度东强西弱;东部高压-超高压变质岩或晚三叠世岩体可能暴露于早侏罗世,而西部则到了中侏罗世.
The Jiyuan Basin in western Henan Province is located in the northern part of the Qinling orogenic belt and is a syndeogenic basin of the Triassic-Jurassic Qinling orogenic belt. The detrital zircon samples of the Middle Triassic-Middle Jurassic 6 groups in the Jiyuan Basin were subjected to LA U-Pb dating of ICP-MS. The results show that the detrital zircon ages are mainly distributed in the following intervals: 2.9-1.7Ga, 1.6-1.0Ga, 1.0-0.8Ga, 800-650Ma, 520-380Ma, 245Ma and ~ 220Ma, except that the detrital zircons 2.9 ~ 1.7Ga mainly come from the North China Craton basement. The zircons of other age groups come mainly from the Qinling orogenic belt and show that as the age of the strata gradually In the early Triassic-Early Triassic samples, the main age is 350-245 Ma, and in the late Late Triassic-Early Middle Jurassic samples , 1.6 ~ 1.0Ga, 1.0 ~ 0.8Ga, 800 ~ 650Ma and 520 ~ 380Ma gradually increased. By the middle of Jurassic, 1.6 ~ 1.0Ga and 520 ~ 380Ma still existed in the samples, and ~ 220Ma ages The detrital zircon age structure indicates that the Qinling orogen had its Indosinian experience from the younger caprock to the older basement Compared with the detrital zircon data in Hefei and Huangshi basins, it is found that the detritus intensities are stronger in the east and west than in the weak in the early Jurassic. The eastern high-pressure-ultrahigh-pressure metamorphic rocks or the Late Triassic rock mass may be exposed to the Early Jurassic The world, while the western came to the Jurassic.