Abstract In this paper, the evolution of the fabric and 3D geometry of the Calmayo trondhjemitic pluton (512.1 ± 3.4 Ma; Sierra Chica, Cordoba, Argentina) is analyzed using Anisotropy of Magnetic Susceptibility (AMS) measurements combined with structural and microstructural data. Gravity data reveal that the pluton is a funnel-shaped body resting on one main root zone detected below the central portion of the pluton. The microstructural observations in the trondhjemite rocks show a progressive textural overprint from magmatic, through high-T to low-T solid-state deformation textures. This overprint is interpreted to be a consequence of the dynamic emplacement and local deformation, particularly close to the adjacent Soconcho shear zone. Late oxidation of the magnetic mineral assemblage (martitization of magnetite) is more intense in the central and southern sectors close to the root zone, explaining the flat magnetic response of this area, and contrasting with a noisy domain to the northeast where magnetite is preserved. We propose that the Calmayo pluton was constructed by several pulses that ascended through a root zone or main conduit. This root zone represents feeder dykes that exploited tension fractures linked to the Soconcho shear zone. Fluids responsible for the late oxidation would have followed similar paths through this protracted shear zone.

中文翻译：

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与破译花岗岩结构和位置相关的地质和地球物理方法：来自 Calmayo 岩体的见解（Eastern Sierras Pampeanas，阿根廷）

摘要 在本文中，使用磁化率各向异性 (AMS) 测量值结合结构和显微结构数据分析了 Calmayo trondhjemitic 岩体（512.1 ± 3.4 Ma；Sierra Chica，Cordoba， Argentina）的结构和 3D 几何形状的演化。重力数据显示，岩体是一个漏斗形物体，位于岩体中心部分下方检测到的一个主要根区上。球长岩中的微观结构观察显示出从岩浆到高 T 到低 T 固态变形纹理的渐进纹理叠印。这种叠印被解释为动态侵位和局部变形的结果，特别是靠近相邻的 Soconcho 剪切带。在靠近根区的中部和南部部分，磁性矿物组合的晚期氧化（磁铁矿的马氏体化）更强烈，解释了该地区的平坦磁响应，并与保留磁铁矿的东北部的嘈杂区域形成对比。我们认为 Calmayo 岩体是由通过根区或主管道上升的几个脉冲构成的。该根区代表了利用与 Soconcho 剪切带相连的张力裂缝的馈线堤坝。负责后期氧化的流体将遵循类似的路径通过这个长期剪切带。我们认为 Calmayo 岩体是由通过根区或主管道上升的几个脉冲构成的。该根区代表了利用与 Soconcho 剪切带相连的张力裂缝的馈线堤坝。负责后期氧化的流体将遵循类似的路径通过这个长期剪切带。我们认为 Calmayo 岩体是由通过根区或主管道上升的几个脉冲构成的。该根区代表了利用与 Soconcho 剪切带相连的张力裂缝的馈线堤坝。负责后期氧化的流体将遵循类似的路径通过这个长期剪切带。