<![CDATA[The Sampolakosa Formation in Buton Island, Southeast Sulawesi, Indonesia, is predominantly composed of packstone calcarenite, which is brownish white when fresh and brown when weathered, and contains 57.8% skeletal grains, 34.3% micrite, 6.1% sparry calcite, and 1.8% pores/voids. Petrographic analysis indicates a grain-supported fabric, reflecting deposition in a moderate-energy environment capable of accumulating bioclasts while retaining a micrite matrix. Planktonic foraminiferal assemblages, including Globorotalia plesiotumida, Globorotalia acostaensis, and Globorotalia mayeri, constrain the age of the formation to the Late Miocene (~11–6 Ma), consistent with its stratigraphic position overlying the Tondo Formation and underlying the Wapulaka Formation. Benthic foraminifera, such as Cibicides lobatulus, Lagena sp., Bolivina sp., and Chrysalidina gradata, indicate deposition on a shallow to middle shelf (5–100 m) within a warm, clear tropical carbonate shelf characterized by moderate bottom-water energy, active currents, and generally well-oxygenated conditions with locally reduced oxygen levels. The combination of grain-supported packstone and micrite retention suggests deposition below the fair-weather wave base but influenced by occasional high-energy events, representing a transition from nearshore to middle shelf under relatively stable seabed conditions. These findings provide a robust framework for the biostratigraphy and paleoenvironmental reconstruction of the Sampolakosa Formation, contributing to regional stratigraphic correlations and insights into carbonate depositional systems.]]>
