| 扬子板块西北缘碧口地块南一里花岗岩成因研究 |
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| 关键词:Nanyili granite geochemistry petrogenesis crustal anatexis Bikou block |
| 基金项目:国家自然科学基金(编号: 40872060); 教育部博士点基金(编号: 20096101110001); 西北大学地质学系国家基础科学人才培养基地创新基金(编号: XDCX08-08) |
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| Genesis of Nanyili Granite in Bikou Block, Northwest Margin of Yangtze Plate |
| The Nanyili granite pluton is located in Bikou block on the northwestern margin of the Yangtze Plate. This paper reports the geochemistry of the Nanyili granite and discusses its genesis, ore-forming material source and geological significance. The granite has high SiO2 (70.27%~71.21%), Al2O3 (14.97%~16.19%) and K2O (3.11%~3.83%) content with its A/CNK being 1.04~1.08, low Y (<10.01×10-6) and HREE (e.g., Yb<0.70×10-6). The ∑REE has a range of 73.55×10-6~93.86×10-6, characterized by enrichment of Rb, Th, U, K, Sr and depletion of Ba, Nb, Ta, Ti and P, slightly negative Eu anomalies (δEu=0.67~0.83) and high Sr/Y(33.01~50.53) and (La/Yb)N(15.30~23.04) ratios with strongly fractionated REE patterns. According to these properties, in combination with a comprehensive analysis of the regional geological-tectonic settings, it is thought that the Nanyili granite pluton was formed in a typical post-collsional tectonic environment. It is probable that the collision between the North China and Yangtze plates during the Triassic resulted in obvious thickening of the crust. Under the extension and thinning tectonic mechanism, the metabasaltic and metapelitic rocks of the crust were partially melted through the amphibolitic dehydration. |
| LUO Jin-cheng,LAI Shao-cong,QIN Jiang-feng,HU Rui-zhong.2011.Genesis of Nanyili Granite in Bikou Block, Northwest Margin of Yangtze Plate[J].Acta Geoscientica Sinica,32(5):559-569. |
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