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华北克拉通西部陆块北缘岩石圈地幔特征的初步研究 王亚妹1, 2, William L. Griffin2, 3, 韩宝福1** WANG YaMei, William L. Griffin, HAN BaoFu 北京大学造山带与地壳演化教育部重点实验室，北京大学地球与空间科学学院，北京100871 澳大利亚麦考瑞大学地球与行星科学系GEMOC国家重点实验中心 澳大利亚勘探与找矿CSIRO中心 1. Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University, Beijing 100871, China 2. GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia 3. CSIRO Exploration and Mining, North Ryde, NSW 2113, Australia Wang YM, Griffin WL and Han BF. 2011. A preliminary study on the lithospheric mantle beneath the northern part of the western North China Craton. Acta Petrologica Sinica, 27(9): XXXX-XXXX Abstract Petrology and major- and trace-element compositions of minerals of the peridotite xenoliths from the Liangcheng, Siziwangqi, Sanyitang and Datong suggest that the lithospheric mantle beneath the northern parts of the Western Block and Central Zone of the North China Craton mainly consists of transitional peridotites. It is the relict of the primitive mantle having experienced initial melt extraction and subsequent?metasomatism. The lithospheric mantle beneath the Liangcheng has been subjected to the lowest degree of melt extraction and intermediate metasomatism, which is in accordance with the lower Cr# of spinels and lower Mg# of coexisting clinopyroxenes in the Liangcheng peridotites. The lithospheric mantle beneath the Sanyitang has experienced the highest degree of melt extraction and the strongest metasomatism. The Sanyitang clinopyroxenes, even within one single sample, show large variations in La/Yb and chondrite-normalized REE patterns (from LREE-depleted to LREE-enriched), and the Sanyitang peridotitic minerals show marked enrichment in some trace elements on the rim than in the core. The Datong and Siziwangqi lithospheric mantles have experienced intermediate melt extraction, but weaker metasomatism than the Liangcheng and Sanyitang lithospheric m