• 责任者：Ning Peisong (School of Earth and Space Sciences ; University of Science and Technology of China ; Hefei 230026 ; China) ; Long Qun
• 刊名：Journal of Earth Sciences and Environment
• 出版年：2013
• 卷期：35(4)
• 页码：p.62-76
• issnNo：ISSN1672-6561
• isbnNo：CN61-1423/P

Zircon U-Pb ages, major and trace element contents and Sr-Nd-Pb isotopic composition of whole-rocks from Late Mesozoic intermediate-basic rocks exposed in the northwestern part of western Shandong block were measured. The samples were collected in Jinan, Zouping, Tai＇an and Zhangqiu areas. The results show that geochemical characteristics of these intermediate-basic rocks, which are enriched in large-ion lithosphile elements, depleted in highqield strength elements, and have strong fractionation in light and heavy rare-earth elements, high contents of Sr and low contents of Y and Yb, are similar to that of arc magmatic rocks; according to the results of zircon U-Pb dating, the formation ages of intermediate-basic rocks in Zhangqiu and Tai＇an areas are 124-128 Ma; Sr-Nd isotopic compositions of intermediate-basic rocks collected in the four areas are similar and relatively enriched, and the two-stage Nd model ages focus on 1.85 Ga;Pb isotopic composition of intermediate-basic rock in Zouping area is similar with that of MORB, whereas the rocks in other three areas are significantly similar with ancient crustal material, so that the characteristics probably indicate that the magmas are derived from enriched mantle source transformed by ancient crustal materials of North China block. Possible tectonic scenario for the magma formation of intermediate-basic rock is that during the subduction of Late Mesozoic Pacific plate beneath North China block, the recycle of ancient crustal material of North China block is deep into mantle, and the metasomatism of enriched melting/fluid and overlying North China lithospheric mantle happens, and then partial melting of peridotite from the enriched mantle produces intrusion of Late Mesozoic intermediate-basic rocks in western Shandong block.