Tectonic and magmatic segmentation interlinkage in the central main Ethiopian rift Shimels Wendwesen a,b , Abera Alemu a , Wubamlak Nigussie c,h , Kevin Mickus d,* , Simeneh Wassihun e , Habtamu Wuletawu f , Yoseph Muhabaw g,h a School of Earth Sciences, Addis Ababa University, Addis Ababa, Ethiopia b Department of Geology, Dire Dawa University, Dire Dawa, Ethiopia c Department of Earth Sciences, Memorial University of Newfoundland, St. John’s, NL, Canada d School of Earth, Environment and Sustainability, Missouri State University, Springfeld, United States e Department of Geology, Mekdela Amba University, Tulu Awulia, Ethiopia f Department of Water Resource and Irrigation Engineering, Wallaga University, Nekemte, Ethiopia g Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, United States h School of Earth Sciences, Bahir Dar University, Bahir Dar, Ethiopia A R T I C L E INFO Keywords: Central main Ethiopian rift Gravity model Gravity anomaly Magmatic vs Tectonic segment ABSTRACT The Main Ethiopian Rift (MER) presents a spectrum of rift sector evolution from embryonic continental rifting in the south to incipient oceanic spreading in the north. The central sector of the MER (CMER) remains relatively immature, characterized by strain accommodation through border faults, axial magmatic segments, and off-rift magmatic zones. However, understanding of the tectonic and magmatic segmentation within this sector is relatively incomplete. This study investigates the CMER at a crustal scale, utilizing gravity data to analyze the nature of tectonic segmentation (TS). While previous studies only considered the Aluto-Gedemsa magmatic segment (MS) within the CMER, our work maps three distinct MS for the frst time: Tullu Moye-Gedemsa-MS, Aluto-MS, and Corbetti-Shalla-MS, based on subsurface imaging using gravity data. We fnd that the distribu- tion of surface faults correlates with subsurface magmatic intrusion zones within the Tullu Moye-Gedemsa and Boseti-Kone MS, indicating a clear interlinkage between tectonic and magmatic segmentation and suggesting the TS stage of the region. In contrast, the absence of such association in the Corbetti-Shalla and Aluto-MS regions suggests that the southern section of the CMER may not be in a stage of TS. 1. Introduction Continental breakup occurs as the lithosphere undergoes stretching due to near or far-feld forces (Buck, 2004; Ebinger et al., 2013), leading to the development of normal faults and thinning of the crust. Far feld forces initially caused extension manifested along border faults, continued extension leads to dike intrusion which contributes to overall extension in the latter stages of continental breakup (Casey et al., 2006; Keir et al., 2006; Beutel et al., 2010; Ebinger and Casey, 2001; Ebinger et al., 2013; Medynski et al., 2013; Stab et al., 2016; Medynski et al., 2016). As rifting progresses from continental breakup to seafoor spreading, axial tectonic segmentation (TS) (Carbotte et al., 2016) fa- cilitates further extension (Kurz et al., 2007; Stab et al., 2016). Tecto- nomagmatic segmentation occurs where extension is accommodated by both dike intrusion and brittle deformation (Kurz et al., 2007). However, the evolutionary stage of TS in mature continental rifts is still not completely understood. The East African Rift System (EARS), situated between the Nubian and Somalia plates, stretches from Djibouti in the north to Mozambique in the south (Bonini et al., 2005). The EARS exhibits a spectrum of rifting features, ranging from incipient continental rifting in the south to the transition to continental-oceanic crust in the north (Corti, 2009; Ebinger and Casey, 2001; Woldegabriel et al., 1990) (Fig. 1A). The Main Ethi- opian Rift (MER) constitutes the northern segment of the EARS, linking the Kenya Rift with the Afar triple junction (Ebinger et al., 2000; Bel- lahsen et al., 2003) (Fig. 1A). The MER is composed of the southern (SMER), central (CMER), and northern (NMER) sectors, each charac- terized by differences in the onset of rifting, style of extension and age of * Corresponding author. E-mail address: kevinmickus@missouristate.edu (K. Mickus). Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto https://doi.org/10.1016/j.tecto.2025.230725 Received 18 December 2024; Received in revised form 26 March 2025; Accepted 31 March 2025 Tectonophysics 905 (2025) 230725 Available online 2 April 2025 0040-1951/© 2025 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.