<![CDATA[The Late Miocene–Pliocene represents a key interval of global climate reorganization marked by cooling trends, monsoon intensification, and major changes in Indo-Pacific ocean circulation. This study aims to reconstruct paleoceanographic and paleoclimatic evolution across the Halang–Tapak Formation transition in the Banyumas Basin, southern Central Java, Indonesia, using quantitative analyses of planktonic and benthic foraminifera from nineteen samples collected along the Kali Rajut section. Standard preparation, microsplitting, and normalization techniques were applied, and biostratigraphic analysis based on Blow’s zonation identifies four biozones spanning Zones N16–N20 (Late Miocene to Late Pliocene). The results indicate a progressive increase in warm-water taxa toward the Pliocene, reflecting surface warming, while thermocline-dwelling species record alternating phases of deepening and shoaling, indicating changes in upper-ocean stratification. A short-lived increase in Globigerina bulloides during the upper N18–lower N19 interval suggests episodic upwelling, whereas variations in Pulleniatina primalis indicate higher productivity during the Late Miocene and Late Pliocene and reduced productivity during the stratified Early Pliocene. Benthic assemblages reveal generally well-ventilated bottom waters with stronger bottom-current activity during N16–N17 and N20. Four paleoceanographic phases are recognized, reflecting shifts in thermocline structure, productivity, and circulation driven by the combined influence of monsoon variability and basin-scale oceanographic reorganization linked to Indonesian Seaway restriction. Although located outside the main Indonesian Throughflow pathway, the Banyumas Basin records its indirect influence, underscoring the value of integrated foraminiferal proxies for reconstructing vertical oceanographic variability in tropical regions.]]>
