BULLETIN OF THE MARINE GEOLOGY
Vol 41, No 1 (2026)

LATE MIOCENE–PLIOCENE PALEOCLIMATE AND PALEOCEANOGRAPHY OF HALANG AND TAPAK FORMATION IN PATIKRAJA, BANYUMAS BASIN

Ryan Dwi Wahyu Ardi (Geological Engineering Department, Faculty of Engineering, Jenderal Soedirman University)
Efrilia Mahdilah Nurhidayah (Geological Engineering Department, Faculty of Engineering, Jenderal Soedirman University)
Gentur Waluyo (Geological Engineering Department, Faculty of Engineering, Jenderal Soedirman University)
Akhmad Khahlil Gibran (Department of Petroleum Geology and Sediments, Faculty of Earth Sciences, King Abdulaziz University)
Safira Qatrunnida (Geological Engineering Department, Faculty of Engineering, Jenderal Soedirman University)
Khoiril Anwar Maryunani (Paleontology and Quaternary Geology Research Group, Faculty of Earth Science and Technology, Institut Teknologi Bandung, Jl. Ganesha No.10, Bandung 40132, West Java, Indonesia)
Nadila Novandaru (Doctoral Program of Geological Engineering, Faculty of Earth Science and Technology, Institut Teknologi Bandung)



Article Info

Publish Date
24 Aug 2026

Abstract

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.

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Journal Info

Abbrev

bomg

Publisher

Subject

Earth & Planetary Sciences

Description

Bulletin of the Marine Geology is a scientific journal of Marine geoscience that is published periodically, twice a year (June and December). The publication identification could be recognized on the ISSN 1410-6175 (print) and e-ISSN: 2527-8843 (on-line) twice a year (June & December) and it has ...