西秦岭位于青藏高原东北缘，是特提斯构造域、滨太平洋构造域和古亚洲洋构造域的交接转换带，具有极为特殊的构造环境。本项目在早期预研究和工作积累之上，选择西秦岭多福屯地区和甘加地区出露的晚中生代陆内钠质碱性玄武岩、钾质拉斑玄武岩及相关火山岩为重点剖析对象，在系统的矿物学、岩石学、同位素年代学、主微量和Pb-Sr-Nd等常规地球化学分析相结合的基础上，进一步以Mg同位素和Re-Os同位素为突破口，重点剖析西秦岭晚中生代下覆地幔源区性质、物质组成、热状态、交代作用类型、熔融机制、岩石圈/软流圈相互作用和壳/幔相互作用过程中的相关细节，同时查明碱性玄武岩中特殊橄榄石“捕掳晶”的成因，并将西秦岭晚中生代陆内岩浆作用和深部动力学背景建立有机联系。该研究不仅在非常规同位素探究陆内火山岩成因方面提供了一个重要的研究实例，而且为印度－欧亚大陆碰撞及高原隆升之前西秦岭构造—岩浆演化提供可靠的岩石学和地球化学约束。

Located in the northeastern margin of the Qinghai-Tibet Plateau, West Qinling is tectonically surrounded by the Tethys Domain, Pacific domain and Paleo-Asian Ocean domain, with a very special tectonic background. According to our preliminary study and former research work, this project mainly focuses on the late Mesozoic intracontinental sodic alkali basalts and potassic tholeiitic basalts and associated volcanic rocks in the Duofutun area and Ganjia area, West Qinling. Based on the systematic analyses in terms of mineralogy, petrology, geochronology and conventional geochemical techniques (e.g. major, trace elements and Pb-Sr-Nd isotopes), this project will utilized Mg and Re-Os isotopes as a breakthrough, aiming to dig and discover the mantle characteristic, composition, thermal state, type of metasomatism, partial melting mechanism, interaction between lithosphere and asthenosphere and interaction between crust and mantle beneath West Qinling during the late Mesozoic, as well as the origin of olivine xenocrysts within alkali basalts. This project will closely combine the late Mesozoic magmatism with the deep dynamic process. This study will not only provide an important case study to probe into the origin of the intracontinental volcanic rocks in terms of non-traditional isotopes, but also offer reliably petrological and geochemical constraints on the tectono-magmatic evolution of West Qinling before the India-Eurasia collision and the uplift of Tibet in the late Mesozoic.