镜泊湖地区全新世玄武岩分布在镜泊湖西北方向的“火山口森林”地区和蛤蟆塘地区。这两个地区相距只有15 km ,但其玄武质岩石在岩石学上具有明显的区别 ,前者为碱性橄榄玄武岩 ,后者为白榴石碱玄岩 ,并且具有钛角闪石、金云母和歪长石巨晶 ,而前者则没有这些巨晶。对它们的地球化学特征研究表明 ,两个地区的玄武质岩石虽然均属于偏钠质的碱性玄武岩 ,但是白榴石碱玄岩相对于碱性橄榄玄武岩总体上具有高的 Al2 O3、Na2 O、K2 O含量、强烈富集轻稀土和大离子亲石元素和低的 Mg O、Ca O、Mg#值和 Na/ K比值为特征 ,而它们所含的二辉橄榄岩包体的地球化学特征则刚好与其寄主岩石相反。反演计算表明 ,玄武质岩石的岩石学和地球化学特征的巨大差异不是由同一源区的地幔部分熔融程度造成的。结合 Sr、Nd、Pb同位素数据 ,证明由于在 6 80 0 0～ 34 90年时 ,地幔柱的作用使该区地幔发生不同程度的交代富集作用 ,由此导致了该区地幔的强烈不均一性。相对于碱性橄榄玄武岩 ,白榴石碱玄岩来自于更加富集的地幔源区 ,其地幔的部分熔融程度相对较低 Holocene basalts in the Jingpohu area are distributed in the “crater forest” area and the toad pond area in the northwest of Jingpo Lake. The two areas are only 15 km apart, but their basaltic rocks have a clear petrological distinction: the former is basic olive basalt, the latter is leucite basalt, and has the amphibole, phlogopite and phlogopite Crooked fossil giant crystal, while the former is not the giant crystal. Their geochemical characteristics indicate that although the basaltic rocks in both areas belong to the alkaline sodium basalts, the albite basalts have high Al 2 O 3 and Na 2 O relative to the basic olivine basalts , K 2 O content, strong enrichment of LREE and LILE, and low MgO, CaO, Mg # and Na / K ratios, whereas the geochemistry of the lherzolitic inclusions contained in them The feature is exactly the opposite of its host rock. Inversion calculations show that the great difference in petrology and geochemistry of basaltic rocks is not caused by the partial melting of the mantle in the same source area. Combined with the isotope data of Sr, Nd and Pb, it is proved that mantle plumes have different levels of metasomatism and enrichment due to the mantle plume in 680 0 ~ 34 90 years, which leads to the intense mantle heterogeneity Sex. Relative to the basic olivine basalts, leucite basalts originate from the more enriched mantle source areas, and their mantle partial melting is relatively low