[S-IT19] Coupling of deep Earth and surface processes

[SIT19-P05] Basement Configuration and Structural Delineation in the Southern Makassar Strait Basin Using Gravity and Seismic Data

*Mohammad Andri Syahrir Iskandar^1,2, Kosuke Egawa¹, Yasuhiro Yamada¹ (1.Kyushu University, 2.Marine Geological Institute of Indonesia)

Keywords:South Makassar Strait, basement configuration, rifting, structural geology, tectonic, gravity anomaly

The Makassar Strait is known for its complex structural and tectonic history, shaped by multiple tectonic episodes, including rifting, subsidence, and strike-slip deformation, which have ultimately driven the opening of the Makassar Strait and relevant separation of the Kalimantan and Sulawesi regions (eg, Guntoro, 1999; Pireno and Darussalam, 2010). This research is focused on understanding the structural and tectonic evolution of the South Makassar Strait Basin based on the integrated geophysical gravity and seismic records together with well data. In particular, the research attempts to understand sediment deposition patterns, interpret basin evolution to delineate the tectonic events that controlled its evolution, and characterize basement rock structures to identify their role in basin formation and hydrocarbon potential. The gravity data were converted into Bouguer anomaly maps to consider the process of thinning and thickening of the earth's crust. The significant basin structures such as sequence boundaries and faults were interpreted by 2D seismic sections. The gravity analysis revealed the distribution of high amplitude anomalies probably associated with the basement highs and lows, while the seismic interpretation showed the presense of tilted half grabens in the basement with normal faults, indicator of basin expansion and crustal thinning in the Eocene rifting phase (Guntoro, 1999; Courel et al, 2011)