Identifikasi Umur Batupasir Formasi Bentang di Pangandaran Berdasarkan Kumpulan Nannofosil Gampingan
Abstrak
ABSTRAK
Sebanyak 15 sampel yang terdiri dari batupasir dengan semen karbonat dalam berbagai ukuran butir dari Formasi Bentang di daerah Babakan Kabupaten Pangandaran dianalisis pengamatan mikroskopis dan penentuan umur berdasarkan kumpulan nannofosil gampingan. Sisipan batulempung sesekali muncul di antara batupasir di bagian selatan lokasi pengambilan sampel. Kumpulan nannofosil gampingan umumnya banyak hingga sedikit dan preservation nannofosil terawetkan sedang - baik. Kerangka biostratigrafi terdiri dari 5 (lima) peristiwa Zonal berdasarkan kemunculan 21 spesies nannofosil gampingan. Lima spesies datum nannofosil yaitu terdiri dari kemunculan akhir Coccolithus miopelagicus (Zona 10.613 Ma atau NN8); kemunculan awal Discoaster hamatus (10,541 Ma) dan kemunculan akhir Discoaster hamatus (9.560 Ma) atau Zona NN9-NN10; kemunculan awal Discoaster berggrenii (NN11/NN10); dan interval atas Reticulofenestra kecil (7.167 Ma atau NN11 Zone). Lebih khusus lagi, interval umur pada Formasi Bentang daerah Pangandaran berkorelasi pada Miosen Akhir yaitu dari Zona NN8 hingga Zona NN11. Dominasi Reticulofenestra kecil di Zona NN11 menunjukkan korelasi positif dengan kelimpahan produktivitas coccolith di Formasi Bentang.
Kata Kunci: Formasi Bentang, Nannofosil Gampingan, Miosen Akhir, Pangandaran
ABSTRACT
A total of 15 samples composed of sandstones with carbonate cement in various grain sizes from Bentang Formation in the Babakan area of Pangandaran regency were analyzed for microscopic observation and age determination based on the calcareous nannofossil assemblages. Claystone inserts occasionally appear between these sandstones in the southern part of the sampling location. The calcareous nannofossils assemblages are generally common to few and preservation of sample is moderate to good. The biostratigraphic framework consist of 5 (five) Zonal events based on the occurrences of 21 species of calcareous nannofossil. Five nannofossil datum species are consist of last occurrence of Coccolithus miopelagicus (10.613 Ma or NN8 Zone); first occurrence Discoaster hamatus (10.541 Ma) and last occurrence of Discoaster hamatus (9.560 Ma) or NN9-NN10 Zone; first occurrence of Discoaster berggrenii (NN11/NN10); and top of small Reticulofenestra interval (7.167 Ma or NN11 Zone). More specifically, an age interval at Bentang Formation of Pangandaran area was correlated for the Late Miocene from NN8 Zone to NN11 Zone. The dominance of small Reticulofenestra at NN11 Zone shows a positive correlation with abundance of coccolith productivity in Bentang Formation.
Keywords : Bentang Formation, Calcareous Nannofosils, Late Miocene, Pangandaran
Teks Lengkap:
PDFReferensi
DAFTAR PUSTAKA
Bukry, D. 1971. Discoaster Evolutionary Trends. Micropaleontology. Vol 17:43-52.
Farida, M., Imai, R., dan Sato, T. 2012. Miocene to Pliocene Paleoceanography of the western equatorial Pacific Ocean based on Calcareous Nannofosils. ODP Hole 805B. Open Journal of Geology, 2:72–79.
Gaspersz, G.C.N., Isnaniawardhani, I., Pratiwi, S.D., Nurdrajat., dan Rieuwpassa, L.C. 2020. Biostratigrafi Calcareous Nannofosil Miosen Pada Anggota Batugamping Formasi Pamutuan Pangandaran, Jawa Barat. Bulletins of Scientific Contribution : Geology, 18 : 3.
Haq, B.U., Premoli-Silva, I., dan Lohmann, G.P. 1976. Calcareous plankton paleobiogeographic evidence for major climatic fluctuations in the early Cenozoic Atlantic Ocean. Journal of Geophysical Research, 82:3861-3876.
Imai, R., Sato, T., Chiyonobu, S., dan Iryu, Y. 2020. Reconstruction of Miocene to Pleistocene sea‐surface conditions in the eastern Indian Ocean on the basis of calcareous nannofosil assemblages from ODP Hole 757B. Island Arc, 29.
Nannotax3. 2014 website: http://ina.tmsoc.org/ Nannotax3.http://ina.tmsoc.org/Nannotax3. Date accessed: 31/11/2020.
Martini, E. 1971. Standard tertiary and quaternary calcareous nannoplankton zonation. In: Farinacci, A. (Editor), Proceedings of the second planktonic conference, Rome, 1970, Rome, pp. 737- 785.
McIntyre, A. 1967. Coccoliths as Paleoclimatic Indicators of Pleistocene Glaciation. Science, 158:1314-1317.
Okada, H. dan Bukry, D. 1980. Supplementary Modification and Introduction of Code Numbers to the Low-Latitude Coccolith Biostratigraphic Zonation. Marine Micropaleontology. Dalam: Haq, B.U (Ed.), NannofosilBiostratigraphy, Hutchinson Ross Publishing Company, Pennsylvania, 5: 321- 325
Pratiwi, S.D., dan Sato, T. 2016. Reconstruction of Paleoceanography Significance in the Western Pacific and Atlantic Oceans during the Neogene Based on Calcareous NannofosilProductivity and Size Variations, Related to the Global Tectonic Events. Open J. Geology, 6:931–43.
Raffi, I. dan Backman, J. 2022. The Role Calcareous Nannofosils in building age models for Cenozoic Marine Sediments: a review. Rendiconti Lincei. Scienze Fisiche e Naturali, 33:25–38.
Rieuwpassa, L.C., Isnaniawardhani, I., Pratiwi, S.D., Nurdrajat., dan Gaspersz, G.C.N. 2021. Sebaran Nannofosil Pada Anggota Batugamping Formasi Pamutuan, Pangandaran, Indonesia. . Bulletins of Scientific Contribution : Geology, 19 : 2.
Sato, T., Yuguchi, S., Takayama, T., dan Kameo, K. 2004. Drastic Change In The Geographical Distribution Of The Cold-Water NannofosilCoccolithus pelagicus (Wallich) Schiller at 1.74 Ms In The Late Pliocene, with Special Reference to Glaciation In The Arctic Ocean. Marine Micropaleontology : Japan. 181-193.
Sato, T. dan Chiyonobu, S. 2013. Manual of Microfossil Study. Asakura Publishing Co., Ltd., Japan, 108.
Supriatna, S., Sarmili, L., Sudana, D., dan Koswara, A. 1992. Peta Geologi Lembar Karangnunggal. Pusat Penelitian dan Pengembangan Geologi : Bandung.
Wade, B.S., dan Bown, P.R. 2006. Calcareous nannofosils in extreme environments: The Messinian Salinity Crisis, Polemic Basin, Cyprus. Palaeogeography, Palaeoclimatology, Palaeoecology, 233:271-286.
Wei, W., Villa, G., dan Wise Jr., S.W. 1992. Paleoceanographic implications of Eocene Oligocene calcareous nannofosils from Sites 711 and 748 in the Indian Ocean. In Wise Jr., S.W., Schlich, R., et al. (1992): Proc. Ocean Drill.
Winter, A., Jordon, R.W., dan Roth, P.H. 1994. Biogeography of living coccolithophores in ocean waters. In Winter, A., Siesser, W.G., eds, Coccolithophores, 161–177, Cambridge University Press.
Young, J. R. 1998. Neogene. In: Bown, P.R. (Editor), Calcareous Nannofosil Biostratigraphy. British Micropalaeontological Society Publications Series. Chapman & Hall, London, 225-265.
Young, J.R., Archontikis, O.A., Su, X., dan Pratiwi, S.D. 2021. Nannofosil palaeoecology of Lower Miocene sapropels from IODP Expedition 359, the Maldives. Palaeogeography
DOI: https://doi.org/10.24198/bsc.v20i1.39353
Refbacks
- Saat ini tidak ada refbacks.