| 大别-苏鲁造山带南北两侧晚中生代富钾火山岩的成因：微量元素及Sr-Nd-Pb同位素制约 |
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| 关键词:K-rich volcanic rocks geochemistry source enrichment petrogenesis Dabie-Sulu orogenic belt |
| 基金项目:国家自然科学基金项目(编号:40272035)，国家创新研究群体科学基金项目(编号:40221301) |
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| Petrogenesis of K-rich Volcanic Rocks on the Northern and Southern Sides of the Dabie-Sulu Orogenic Belt,Eastern China:Constraints from Trace Elements and Sr-Nd-Pb Isotopes |
| Late Mesozoic K-rich volcanic rocks,mainly of the trachybasalt-basaltic trachyandesite-trachyandesite-latite-trachyte association,are widely developed on the northern and southern sides of the Dabie-Sulu Orogenic Belt (DSCB). These rocks generally have abundant alkali-and potassium-rich LILE and LREE like Rb and Th,and are depleted in HFSE such as Nb and Ti. They also have high ( 87 Sr/ 86 Sr)_ i ratios and low ε_ Nd ( t ) values. Compared with those on the southern side of DSCB,the K-rich volcanic rocks on the northern side of DSCB have higher total REE contents and higher LREE/HREE and ( 87 Sr/ 86 Sr)_ i ratios but much lower ε_ Nd ( t ) and 206 Pb/ 204 Pb values. Combined element-isotope tracing demonstrates that the studied K-rich volcanic rocks all originated from partial melting of the enriched mantle. However,the mantle source on the northern side of DSCB may be quite different from that on the southern side in the enrichment process. The formation of the enriched mantle on the southern side of DSCB is mainly related to metasomatism by fluids from dehydration of subducted oceanic crust materials,whereas the mantle source on the northern side of DSCB was subjected to the involvement of subducted Yangtze continental crust materials besides the influence of subducted oceanic crust materials. The involvement of continental crust materials in the mantle source is considered to be the main factor responsible for the geochemical differences of the K-rich volcanic rocks between the northern side and the southern side of DSCB. |
| QIU Jian-sheng,JIANG Shao-yong,ZHANG Xiao-lin,HU Jian.2004.Petrogenesis of K-rich Volcanic Rocks on the Northern and Southern Sides of the Dabie-Sulu Orogenic Belt,Eastern China:Constraints from Trace Elements and Sr-Nd-Pb Isotopes[J].Acta Geoscientica Sinica,25(2):255-262. |
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