| 印度洋Carlsberg洋脊玄武岩岩石地球化学特征及其地质意义 |
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| 引用本文： | 淳明浩,于增慧,翟世奎.印度洋Carlsberg洋脊玄武岩岩石地球化学特征及其地质意义[J].海洋学报,2015,37(8):47-62. |
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| 作者姓名： | 淳明浩 于增慧 翟世奎 |
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| 作者单位： | 1.中国海洋大学 海洋地球科学学院 海底科学与探测技术教育部重点实验室, 山东 青岛 266100;中国石油集团工程技术研究院, 天津 300451 |
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| 基金项目： | 国家重点基础研究发展计划项目(2013CB429702);中国大洋矿产资源研究开发协会"十二五"重大项目 (DY125-11-R-01,DY125-12-R-03)。 |
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| 摘 要： | 本文对采自印度洋Carlsberg脊14个站位的新鲜玄武岩样品进行了常量和微量元素组成分析,旨在研究岩浆源区地幔的性质以及岩浆作用过程。研究结果表明:该区玄武岩为典型的源于亏损型地幔的大洋中脊玄武岩,不同样品经历了不同程度的结晶分异作用,演化过程主要受控于橄榄石的结晶分异作用,部分样品中有单斜辉石结晶分异作用的影响,斜长石的结晶分异作用不显著;玄武岩岩浆来源于亏损型尖晶石二辉橄榄岩地幔的熔融,主微量元素组成中尚未见到富集型组分混入的证据;源区地幔不同比例的熔融作用及其后岩浆演化过程的差异是造成不同样品间地球化学性质差异的主要原因,彼此独立的局部岩浆作用过程是岩浆作用差异的主控制因素。Carlsberg脊玄武岩整体与全球标准大洋中脊玄武岩(N-MORB)平均组分相近,不同脊段间岩浆源区地幔的组成、熔融程度(比例)和熔融深度等无明显差异,这种特征向南直到CIR的北段。
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| 关 键 词： | 印度洋 Carlsberg脊 玄武岩 岩石地球化学 地幔熔融 结晶演化 |
| 收稿时间： | 2/9/2015 12:00:00 AM |
| 修稿时间： | 2015/6/19 0:00:00 |
The geochemistry and geological significances of basalts from Carlsberg Ridge in Indian Ocean |
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| Chun Minghao,Yu Zenghui and Zhai Shikui.The geochemistry and geological significances of basalts from Carlsberg Ridge in Indian Ocean[J].Acta Oceanologica Sinica (in Chinese),2015,37(8):47-62. |
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| Authors: | Chun Minghao Yu Zenghui and Zhai Shikui |
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| Institution: | 1.The Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Ocean University of China, Qingdao 266100, China;CNPC Research Institute of Engineering Techology, Tianjin 300451, China2.The Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Ocean University of China, Qingdao 266100, China |
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| Abstract: | Major and ICP-MS trace element compositions have been determined for 14 fresh mid-ocean ridge basalts (MORBs) dredged from Carlsberg Ridge to investigate the nature of mantle source and magmatic process beneath this ridge. These basalts can be classified into the typical normal MORB derived from depleted mantle source and basalts with different geochemistry experienced variable degree of fractional crystallization which is mainly dominated by olivine fractionation, a few of basalts have experienced clinopyroxene fractionation and no significant plagioclase fractionation. The basaltic magma is derived from the depleted spinel lherzolite mantle melting and has no obvious major and trace element geochemical evidence suggested the enriched component mixing into the mantle source. The distinct geochemical characteristics for basalts are mainly controlled by various degree of mantle melting and the subsequently different magmatic evolution processes, and the independent magmatic process in different segments is the main dominating factor for differences of magmatism in this ridge. Major and trace element compositions of MORBs from Carlsberg Ridge are very similar to the average composition of global normal mid-ocean ridge basalt (N-MORB), there are no significant differences for compositions of mantle sources, and the average degree and depth of mantle melting among segments of Carlsberg Ridge, and this homogeneity feature continues southward to the northern section of the CIR. |
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| Keywords: | Indian Ocean Carlsberg Ridge basalts geochemistry mantle melting crystallization evolution |
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