學術資源整合系統-相關推薦
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| 作者 | Lee Y.T.,Chan J.C., Juang W.S. |
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| 出版日期 | 2006 |
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| 著作名稱 | Geochemistry of Cenozoic basaltic rocks from Shandong Province and
its implication for mantle process in North China
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| 卷 | Vol.40.pp.579-596. |
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| 摘要 | Cenozoic (Miocene to Pleistocene) basaltic rocks found in Shandong province of northern China include tholeiite,
olivine tholeiite and alkali basalt. We present major, trace and rare earth elements data of these basalts and together with
Sr-Nd isotopic data in the literatures to discuss the petrogenesis of these basalts. The basalts from Penglai area have
higher K, Na and P and incompatible elements, but lower Ca, Mg and compatible elements contents than those from
Changle area of Shandong province. Spidergrams indicate that Cenozoic basalts from Shandong province have geochemical
characteristics similar to those of ocean island basalts (OIB) with slight positive Nb anomaly. The negative Ba, Rb and K
anomalies found in the alkali basalts suggest the presence of residual phlogopite in the mantle source, indicating a
metasomatic event occurred before the partial melting. The 143Nd/144Nd vs. 87Sr/86Sr plot suggested that basalts from
Shandong province can be produced by MORB and EM-I components mixing. We propose that the EM-I type lithospheric
mantle may have been produced by the recent H2O-CO2 -fluids metasomatism and the fluids may be derived from dehydration
of the subducted slab.
Based on Shaw’s equation, the basalts from eastern and central Shandong province have undergone different degrees
of partial melting from the mantle source. Degrees of partial melting and chemical composition of basalts from Shandong
province suggest that the lithosphere has thickened progressively since the Miocene. On the basis of Ar-Ar ages of this
study and the fractional crystallization model proposed by Brooks and Nielsen (1982), we suggest that basalts from Changle
and Penglai areas belong to different magmatic systems which have undergone fractional crystallization and evolved
progressively to produce other types of basalts. |
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| 系統號 | NO000002990 |
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