Eocene Paleoclimatic Implications in the Bayat Basin Based on Nannofossil Distribution

Muhammad Rifa'i; Siti Umiyatun Choiriah; Akmaluddin

Authors

Muhammad Rifa'i Department of Geology Engineering, Faculty of Mineral Technology, UPN “Veteran” Yogyakarta, Depok, Sleman, Yogyakarta 55283, Indonesia
Siti Umiyatun Choiriah Department of Geology Engineering, Faculty of Mineral Technology, UPN “Veteran” Yogyakarta, Depok, Sleman, Yogyakarta 55283, Indonesia
Akmaluddin Department of Geological Engineering, Faculty of Engineering, Universitas Gadjah Mada

Keywords:

Eocene, Bayat, Gamping Wungkal, Calcareous Nannofossil, Paleoclimate

Abstract

The Middle–Late Eocene represents a critical interval of greenhouse climate evolution following the Early Eocene Climatic Optimum (EECO), yet quantitative paleoclimate records from low-latitude Southeast Asia remain scarce. This study presents a multi-proxy calcareous nannofossil-based reconstruction of surface-water conditions from the Gamping–Wungkal Formation in the Bayat Basin, southern Java. Detailed stratigraphic logging and systematic sampling along a 60 m section were combined with quantitative assemblage analysis and Scanning Electron Microscope validation. Biostratigraphic evaluation assigns the studied interval to the NP17 zone (Middle–Late Eocene). Paleoclimatic reconstruction integrates the Reticulofenestra Size Ratio (RSR), Warm-Water Index (WWI), Discoaster Abundance Ratio (DAR), and total Reticulofenestra abundance. Assemblages are dominated by medium- to large-sized Reticulofenestra and persistent Discoaster occurrences, indicating warm, oligotrophic, and stratified surface-water conditions. Despite global post-EECO cooling trends documented in mid- and high-latitude records, the Bayat data suggest sustained tropical greenhouse conditions during NP17. These findings are consistent with emerging evidence of latitudinal variability in Eocene climate evolution and establish the Bayat Basin as an important low-latitude archive for evaluating Paleogene greenhouse dynamics in Southeast Asia.

Downloads

Download data is not yet available.

References

Agnini, C., Fornaciari, E., Raffi, I., Catanzariti, R., Pälike, H., Backman, J., Rio, D., 2014. Biozonation and Biochronology of Paleogene Calcareous Nannofossils from Low and Middle Latitudes. Newsletters Stratigr. 47, 131–181.

Agnini, C., Monechi, S., Raffi, I., 2017. Calcareous Nannofossil Biostratigraphy: Historical Background and Application in Cenozoic Chronostratigraphy. Lethaia 50, 447–463.

Blaj, T., Backman, J., Raffi, I., 2023. Late Eocene to Oligocene preservation history and biochronology of calcareous nannofossils from paleo-equatorial Pacific Ocean sediments. Riv. Ital. di Paleontol. e Stratigr. 129, 457–483.

Fang, S., Xi, D., Sun, Q., Li, D., 2024. The bivalve-bearing carbonate platform on the east Tethys during the middle Eocene and its response to the Tethys transgression 1–15.

Farida, M., Jaya, A., Ahmad, A., Nugraha, J., 2024. The Eocene to Oligocene boundary and paleoclimatic indications based on calcareous nannofossils of Tonasa Formation, South Sulawesi, Indonesia. Foss. Rec. 27, 221–231.

Fokkema, C.D., Agterhuis, T., Gerritsma, D., Goeij, M. De, Liu, X., Regt, P. De, 2024. Polar amplification of orbital-scale climate variability in the early Eocene greenhouse world 1303–1325.

Gallagher, S.J., Auer, G., Brierley, C.M., Fulthorpe, C.S., Hall, R., 2024. Cenozoic History of the Indonesian Gateway. Annu. Rev. Earth Planet. Sci. 52, 581–604.

Ghandour, I.M., Balc, R., Faris, M., Helal, S., Mosa, G.A., Aljahdali, M.H., 2023. New Insight into the Middle Eocene Calcareous Nannoplankton Biostratigraphy and Paleoenvironment from Fayoum and Beni Suef Areas, Egypt 129, 343–359.

Hall, R., 2019. The Plate Tectonics of Indonesia and Surrounding Regions. Geol. Soc. London, Spec. Publ. 355, 1–24.

Hall, R., 2011. Australia--SE Asia Collision: Plate Tectonics and Crustal Flow, in: Hall, R., Cottam, M.A., Wilson, M.E.J. (Eds.), The SE Asian Gateway: History and Tectonics of the Australia--Asia Collision, Geological Society, London, Special Publications. pp. 75–109.

Hidayat, E., Muslim, D., Zakaria, Z., Permana, H., Wibowo, D.A., 2021. Tectonic Geomorphology of the Karangsambung Area , Central Java , Indonesia 85–105.

Hollis, C.J., Naeher, S., Clowes, C.D., Naafs, B.D.A., Pancost, R.D., Taylor, K.W.R., Dahl, J., Li, X., Ventura, G.T., Sykes, R., 2022. Late Paleocene CO 2 drawdown , climatic cooling and terrestrial denudation in the southwest Pacific.

Hutchinson, D.K., Coxall, H.K., Lunt, D.J., Steinthorsdottir, M., Boer, A.M. De, Baatsen, M., Heydt, A. Von Der, Huber, M., Kennedy-asser, A.T., Kunzmann, L., 2021. The Eocene – Oligocene transition : a review of marine and terrestrial proxy data , models and model – data comparisons 269–315.

Jatiningrum, R.S., Saputra, R., Phang, G., Sato, T., 2022. Sedimentation rates and calcareous nannofossil biostratigraphy of the Nanggulan Formation, Kulon Progo, Indonesia. Bull. Mar. Geol. 37.

Judd, E.J., Tierney, J.E., Huber, B.T., Wing, S.L., Lunt, D.J., Ford, H.L., Inglis, G.N., Mcclymont, E.L., Brien, C.L.O., Rattanasriampaipong, R., Si, W., Staitis, M.L., Thirumalai, K., Anagnostou, E., Cramwinckel, M.J., Dawson, R.R., Evans, D., Gray, W.R., Grossman, E.L., Henehan, M.J., Hupp, B.N., Macleod, K.G., Connor, L.K.O., Luisa, M., Montes, S., Song, H., 2022. The PhanSST global database of Phanerozoic sea surface temperature proxy data.

Luan, X., Lunt, P., 2021. Journal of Asian Earth Sciences Latest Eocene and Oligocene tectonic controls on carbonate deposition in eastern Java and the south Makassar Straits , Indonesia. J. Asian Earth Sci. 220, 104900.

Lunt, D.J., Luan, X., 2023. Cenozoic tectonic reorganization of Southeast Asia and implications for regional paleoclimate. Glob. Planet. Change 226, 104097.

Lunt, P., 2023. Cenozoic Isolated Carbonate Platforms of Southeast Asia, in: Cenozoic Isolated Carbonate Platforms, SEPM Special Publication. SEPM (Society for Sedimentary Geology).

Ma, R., Aubry, M., Bord, D., Jin, X., Liu, C., 2024. Inferred nutrient forcing on the late middle Eocene to early Oligocene ( ∼ 40 – 31 Ma ) evolution of the coccolithophore Reticulofenestra ( order Isochrysidales ).

Menini, A., Mattioli, E., Vinçon-laugier, A., Suan, G., 2021. Paleocene-Eocene Thermal Maximum Pr ub Ar tic Pr eP ub Ar tic.

Mulyaningsih, S., 2016. Volcanostratigraphic Sequences of Kebo–Butak Formation at Bayat Geological Field Complex, Central Java Province and Yogyakarta Special Province, Indonesia. Indones. J. Geosci. 3, 77–94.

Novita, D., Barianto, D.H., Novian, M.I., 2014. Planktonic foraminifera biozonation of the Middle Eocene–Oligocene Kebo Formation, Bayat, Central Java. Ber. Sedimentol. 31, 70–78.

Okada, H., Honjo, S., 1973. The distribution of oceanic coccolithophorids in the Pacific. Deep Sea Res. 20, 355–374.

Pearson, P.N., Foster, G.L., Wade, B.S., 2015. Atmospheric Carbon Dioxide through the Eocene--Oligocene Climate Transition. Nature 461, 1110–1113.

Raffi, I., Backman, J., Backman, J., 2022. The role of calcareous nannofossils in building age models for Cenozoic marine sediments : a review. Rend. Lincei. Sci. Fis. e Nat. 33, 25–38.

Ratumanan, R.C.F., Isnaniawardhani, V., Muljana, B., 2023. Middle Eocene nannofossil assemblages responding to depositional dynamics of the Elat Formation, Maluku. J. GeoCelebes 7, 138–153.

Samudra, S., Sutisna, K., 1992. Peta Geologi Lembar Klaten, Jawa, Skala 1:100.000.

Surono, 2009. Litostratigrafi Pegunungan Selatan Bagian Timur Daerah Istimewa Yogyakarta dan Jawa Tengah. J. Geol. dan Sumberd. Miner. 19, 209–221.

Umiyatun, S., Kurniawan, R.E.J., Prastistho, B., Geologi, P.S., Klaten, K., Tengah, J., 2006. Studi Nannofosil Pada Satuan Batulempung Formasi Wungkal-Gamping Lintasan Watuprahu. Proceeding PIT IAGI 35, 21–22.

Villa, G., Persico, D., Florindo, F., others, 2021. Integrated calcareous nannofossil and magnetostratigraphic record of ODP Site 709: Middle Eocene to Oligocene paleoceanography of the equatorial Indian Ocean. Mar. Micropaleontol. 169, 102051.

Westerhold, T., Agnini, C., Anagnostou, E., Hilgen, F., Hönisch, B., Pälike, H., Wade, B., Sosdian, S., Kasbohm, J., 2024. Timing Is Everything.

Westerhold, T., Marwan, N., Drury, A.J., others, 2021. An astronomically dated record of Earth’s climate and its predictability over the last 66 million years. Science (80-. ). 369, 1383–1387.