【摘要】 郯庐断裂带张八岭隆起北段分布着一些晚中生代岩体,其侵位时间在120~128 Ma之间,稍晚于同期华北克拉通内江苏徐州和安徽宿州地区(简称徐宿地区)。文章通过对上述两地区的地球化学特征的对比研究,认为张八岭隆起北段岩体的岩浆来源可能是壳-幔岩浆混合形成的,并可能经历了一定的岩浆分异作用;而徐宿地区岩浆可能与深部地壳物质的部分熔融有关。上述结果表明,张八岭隆起北段岩浆来源深度较华北克拉通内部徐宿地区深,断裂带内具有较强的伸展活动及岩石圈减薄程度。分析认为,断裂带的存在和活动在岩石圈减薄过程中具有诱发和促进作用。更多还原

【Abstract】 Emplacement ages(120～128 Ma) of the late Mesozoic intrusions from the northern segment of Zhangbaling uplift belt along the Tan-Lu fault are later than Mesozoic intrusive complex in the Xuzhou-Suzhou areas.Based on their geochemical characteristics,Zhangbaling intrusions imply that magma sources should be a mixing of melting between the crust and the mantle,and experienced a certain extent crystallization.However,the intrusive complex in the Xuzhou-Suzhou areas mostly derived from the partial melting of the lower crust.Investigations indicate that the depth of magmatic origin in Zhangbaling uplift belt was deeper than the Xuzhou-Suzhou areas compared with inner North China Craton.The Tan-Lu fault zone had intensive extensive activities and lithosphere thinning degree.Therefore,the occurrence and activities of the fault zone played an inducing and promoting role in magmatic activities during lithosphere thinning.更多还原