Abstract Gran Canaria, one of the two main islands of the Canary Archipelago off NW Africa, has been volcanically active for at least 15 million years. The island went through several volcanic cycles that varied greatly in composition and extrusive and intrusive activity. The complex orography of the island has excluded extensive land geophysical surveys on the island. A review of the available geophysical information on the island shows that it has been obtained mainly through marine and airborne geophysical surveys. A new dataset comprising 100 magnetotelluric soundings acquired on land has been used to obtain the first 3D electrical resistivity model of the island at crustal scale. The model shows high resistivity values close to the surface in the exposed Tejeda Caldera that extends at depth to the SE cutting the islands in half. Outside the inferred limits of the Tejeda Caldera the 3D model shows low resistivity values that could be explained by hydrothermal alteration at deeper levels and the presence of marine saltwater intrusion at shallower levels near the coast. The presence of unconnected vertical-like structures, with very low resistivity (

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大加那利岛使用大地电磁数据的 3D 电阻率

摘要 大加那利岛是非洲西北部加那利群岛的两个主要岛屿之一，火山活动至少已有 1500 万年。该岛经历了几次火山循环，在成分和喷出和侵入活动方面变化很大。岛上复杂的地形排除了岛上广泛的陆地地球物理调查。对岛上现有地球物理信息的审查表明，这些信息主要是通过海洋和航空地球物理调查获得的。一个包含 100 个在陆地上获得的大地电磁测深的新数据集已被用于获得该岛在地壳尺度上的第一个 3D 电阻率模型。该模型显示了靠近暴露的 Tejeda Caldera 表面的高电阻率值，该火山口在深处延伸到 SE 将岛屿切成两半。在 Tejeda Caldera 推断的界限之外，3D 模型显示低电阻率值，这可以通过更深层次的热液蚀变和靠近海岸的较浅层次的海洋咸水侵入来解释。存在未连接的垂直状结构，电阻率非常低（