| 崂山地区玄武质岩石的地球化学特征 |
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| 引用本文： | 赵广涛,韩宗珠,栾光忠,邢光福,陈佐林.崂山地区玄武质岩石的地球化学特征[J].高校地质学报,2001,7(4):435-443. |
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| 作者姓名： | 赵广涛 韩宗珠 栾光忠 邢光福 陈佐林 |
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| 作者单位： | 1. 青岛海洋大学海洋地球科学学院，山东 青岛 266003; 2. 南京地质矿产研究所，江苏 南京 210016 |
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| 基金项目： | 国家自然科学基金 (4 990 30 0 3)，山东省自然科学基金 (Y2 0 0 0E6 )资助项目 |
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| 摘 要： | 晚白垩世（95Ma)，白垩纪末（69Ma)和古新(6765Ma)玄武质岩石，呈脉状零星露头产于燕山期崂山岗岩体中，岩性分别为碱性玄武岩，碧岩和斑玄武岩，碱性玄武岩和碧玄岩以高度富集LILE和LREE为特征，（La/Yb)N=25.5-46.6，两者表现为程度不等的Nb,Ta,Zt,Ti等高场强元素亏损，与我国华北新生代碱性玄武岩相比，Ba,Rb,Th更为富集，Sr,Nd同位素比值（碧玄岩）为^87Sr/^86Sr=0.705517,^143Nd/^144Nd=0.512777.它们很可能均起源一刊中生代扬子板块玄武岩类似，微量元素总量及LILE和LREE含量均较低，（La/Yb)N=4.7-6.4，其典型的微量元素比值（如Zr/Nb,Rb/Nb,Nb,Ta等）与EM1型OIB类似，^87Sr/686Sr=0.706054-0.706146;^143Nd/^144Nd=0.572387-0.512392,它可能起于受上涌软流圈交代的大陆岩石圈（软流圈顶部的“metasome”）的部分熔融，是软流圈流体与大陆岩石圈相互作用的产物。上述不同类型玄武岩的顺序侵位，可能反映在晚白垩世一早第三纪期间，本区曾经历地壳拉张强度逐渐增大一地壳持续减薄－软流圈不断上涌的动力学过程。
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| 关 键 词： | 玄武质岩石 岩石地球化学 崂山 山东 微量元素 锶同位素 大陆岩石圈 钕同位素 |
| 文章编号： | 1006-7493(2001)04-435-09 |
| 收稿时间： | 2001-12-20 |
| 修稿时间： | 2001年5月8日 |
Geochemistry of Basalitic Rocks in the Laoshan Mountain Area |
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| ZHAO Guang tao ,HAN Zong zhu ,LUAN Guang zhong ,XING Guang fu ,CHEN Zuo lin.Geochemistry of Basalitic Rocks in the Laoshan Mountain Area[J].Geological Journal of China Universities,2001,7(4):435-443. |
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| Authors: | ZHAO Guang tao HAN Zong zhu LUAN Guang zhong XING Guang fu CHEN Zuo lin |
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| Institution: | 1. College of Marine Geoscience, Qindao University of Oceanography, Qindao 266003, China; 2. Nanjing Institute of Geology and Mineral Resouces, Nanjing 210016, China |
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| Abstract: | The scattered outcrops of the Late Creraceous(95Ma), end Creraceous (69Ma), and the Oligocene(67-65Ma)basalitic rocks occur in the Laoshan Yanshanian granitite intrussives, eastern China. The rock types are alkaili-basalt, basanite and tholeiite, respectively. The alkai1i-basalt and basanite are all characterized by higher contents of LILE and LREE, with(La/Yb)N=25.5～46.6, depleted in Nb, Ta, Zr, Ti, and enriched in Ba, Rb, Th, as compared to those of the Cenozoic alkaili-basalt in North China The Sr, Nd isotopic ratios of basanite are 87Sr/86Sr=0.705517, Nd/ Nd= 0.572777. Both alkaiti-basalt and basanite should be derived by partial melting of an older mantle wedge that formed by the Early Mesozoic subduction of the Yangtze plate beneath the North China plate. Compared to alkaili-basalt and basanite, the
tholeiite has lower contents of total trace elements, LILE and LREE, and with (La/Yb)N=4.7～6.4. Their typical ratios of trace elements axe similar to those of EM1-OIB 87Sr/88Sr=0.706054～0.706146; 143Nd/144Nd = 0.572387～0.512392. They should be originated by partia1 melting from the “metasome” -the lithospheric mantle metasomatised by the rising asthenospheric fluid. The intrusions of different kinds of basalts may reflect the dynamic process in the area of gradual crustal extension, thinning, and asthenospheric elevation from Late Creraceous to Eogene. |
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| Keywords: | basalitic rocks petro geochemistry Laoshan Mountain area Shandong Province |
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