• 责任者：Xu Rong (State Key Laboratory of Geological Process and Mineral Resources ; Faculty of Earth Sciences ; China University of Geosciences ; Wuhan 430074 ; China) ; Liu Yongsheng
• 刊名：Acta Petrologica et Mineralogica
• 出版年：2013
• 卷期：32(5)
• 关键词：橄榄岩 ; peridotites ; 岩石圈地幔 ; lithospheric mantle ; 辽宁 ; Liaoning Province
• 页码：p.613-636
• 图表：11 illus., 5 tables, 98 refs.
• 分类号：0801
• issnNo：ISSN1000-6524
• isbnNo：CN11-1966/P

     Mantle peridotite xenoliths entrained in the Cenozoic alkaline basalts from Kuandian of eastern North China Craton provide important constraints on the nature and evolution of the lithospheric mantle beneath this area. Two types of xenoliths can be defined based on the Mg# of their olivines： Type 1 low-Mg# lherzolites are characterized by low Mg# in olivines （89.8--90.3）, high TIO2（0.38% N0.57% ）, A1203（4.41% --6.87% ）,FeOT（2.46% -- 3.73%）, MnO （0.08% -- 0.11%） content and low Cr~ （7.42-- 14.2） in the coexisting clinopyroxenes, and have undergone low degrees of partial melting; these characteristics are similar to those of low-Mg~ peridotites in the Late Cretaceous and Cenozoic basahs, thus probably representing newly accreted lithospheric mantle. Type 2 high-Mg# harzburgites are characterized by high Mg# in olivines （91.0-- 92.3）, low TiO2（0.03% --0.33%）, Al2O3（2.27% --5.49%）, FeOT（2.04% --2.40%）, MnO （0.07% --0.08%） content and high Cr# （15.3--25.8） in the coexisting clinopyroxenes and have undergone high degrees of partial melting; these refractory geochemical characteristics are completely different from those of low-Mg# lherzolites, but similar to those of high-Mg# peridotite xenoliths from Arehean and Proterozoic lithospheric mantle in the craton, therefore are considered to be relicts of ancient lithospheric mantle. The nonexistence of obvious differ- ences in equilibrium temperatures of low-Mg# and high-Mg# peridotites suggests that there is no significant stratification within the sub-continental lithospheric mantle beneath Kuandian, but there exists mixture between the newly accreted mantle and the ancient lithospheric mantle. Trace element characteristics of the Kuandian peridotite xenoliths indicate that they have undergone multiple complex mantle metasomatism, and the metaso- matic agents include not only silicate melts/fluids but also carbonate melts; both melts/fluids released by Pacific  slab subduction and the heat perturbation and upwelling of hot asthenospheric melts caused by subduction were  involved in their provenance, and thus Pacific slab subduction might have played an important role in the destruction of the North China Craton.