中文摘要：

在 Yangyuan 在第三级的碱暗岩招待的披风捕虏体， HebeiProvince，定位了到太行山严肃貌的西方，包括 Iherzolites， harzburgites 和辉岩。在橄榄石模式对 Fo 的阴谋，大多数 Yangyuan 橄榄岩从海洋的趋势背离，在这些地以内掉落太古代并且原生地披风。有从 -6.9 to-10.6 和 ~(87 )的 epsilon_(Nd ) 的充实 SomeLREE 的样品展览 EMI 类型同位素的签名从 0.7044 ～ 0.7047 的 Sr/~(86 ) Sr。由对比，另一件 LREE-en-riched 样品有积极 epsilon_(Nd )(+5.7 ) 类似于那为弄空 LREE 的橄榄岩。这观察建议在 Yangyuan 下面的上面的披风经历了一个多级式的交代作用。给那 EMI 类型同位素的签名通常在 ancientcratons 下面在岩石圈披风被观察的事实， Yangyuan 捕虏体的同位素的作文在西方的诺思中国下面为旧岩石圈披风的存在提供新证据。

英文摘要：

Mantle xenoliths hosted in Tertiary alkali basalts in Yangyuan, Hebei Province, located to the west of the Taihangshan gravity lineament, include Iherzolites, harzburgites and pyroxenite. In the plot of olivine mode vs Fo, most of the Yangyuan peridotites deviate from the oceanic trend, falling within the fields of Archean and Proterozoic mantles. Some LREE- enriched samples exhibit EMI-type isotopic signature with εNd ranging from -6.9 to -10.6 and ^87Sr/^86Sr from 0.7044 to 0.7047. By contrast, another LREE-en- riched sample has a positive εNd （＋5.7） similar to that for LREE-depleted peridotites. This observation suggests that the upper mantle beneath Yangyuan underwent a multi-stage metasomatism. Given the fact that EMI-type isotopic signature is usually observed in the lithosphere mantle underneath ancient cratons, the isotopic composition of the Yangyuan xenoliths provides new evidence for the existence of the old lithosphere mantle beneath western North China.