Tectonic Framework of the Arenópolis and Anicuns‐Itaberaí Segments of the Goiás Magmatic Arc Based on 3D Magnetotelluric Inversion

Abstract The Goiás Magmatic Arc (GMA) is a Neoproterozoic juvenile terrain formed through oceanic‐oceanic and oceanic‐continental subduction. It comprises three main segments: Mara Rosa, Anicuns‐Itaberaí (GMAAI), and Arenópolis (GMAA), whose tectonic evolution and connectivity remain uncertain. Debate persists on: (a) whether these segments evolved together from the start or were juxtaposed during collision; (b) metallogenic models lack information on the lower crust and upper mantle, essential for fertility analysis; (c) why the Cretaceous Goiás Alkaline Province (GAP) outcrops exclusively in the GMAA. To address these questions, we conducted a long‐period magnetotelluric survey (34 stations, 10–13,000 s) across the GMAA/GMAAI. The resulting 3D resistivity model (nRMS = 1.21) reveals distinct lithospheric structures. GMAA exhibits significant crustal thickness and resistivity variations, while GMAAI shows higher resistivity and a thicker lithosphere, which likely controlled the confinement of the GAP within the GMAA. The absence of a continuous conductor along the Moiporá‐Novo Brasil shear zone suggests that these segments may be splays of the Transbrasiliano Lineament. Thus, the GMAA and GMAAI likely evolved along the same subduction front, amalgamating in the final stages of the Brasiliano orogeny. Three major conductors were identified: C1, associated with the Bom Jardim deposit (Cu); C2, linked to the Americano do Brasil deposit (Ni–Cu sulfide); and C3, related to the Caldas Novas geothermal anomaly. These findings provide new insights into the GMA's tectonic evolution and metallogenic significance, revealing deep conductive zones linked to known mineral deposits and highlighting the control exerted by lithospheric architecture in the region.