Proceeding of the 5 th International Conference of Geological Engineering Faculty, Vol. 1, Issue 1, 2020, pp. 46-54 Copyright © 2020 TIIKM ISSN 2783-8625 online DOI: https://doi.org/10.17501/27838625.2020.1105 Corresponding Authors’ Deatils: lilian17001@mail.unpad.ac.id Planktonic and Benthic Foraminifera Miocene on Sandstone Unit of Bentang Formation in Pangandaran, West Java Lilian C. Rieuwpassa 1* , Gabriela C. N. Gaspersz 2 , Vijaya Isnaniawardhani 2 and Santi Dwi Pratiwi 2 1 Undergraduate Program of Geological Engineering, Universitas Padjadjaran, Bandung, Indonesia 2 Department of Geoscience, Faculty of Geological Engineering, Universitas Padjadjaran, Bandung Jalan Raya Bandung- Sumedang Km.21 Jatinangor, Kab. Sumedang 45363, Jawa Barat, Indonesia Abstract: The research in Pangandaran was due to the presence of exposed rock lithology and the presence of fossil content, either macrofossil or microfossil. Research sites are located at 108°27'46.55'' to 108°30'29.88''E and 7°41'35.54'' to 6°38'53.60''. This study was conducted to determine the distribution of foraminifera contained in the constituent sandstone units of the Bentang Formation. The research was conducted at 7 (seven) points of location of sandstone outcrops. Analysis and identification of foraminifera using a binocular microscope after foraminifera preparation. The distribution areas of the sandstone units of the study area are in the Cimanggu, Bula Krandu and Karangbenda areas. Age datum markers that are characterized by planktonic foraminifera fossils, namely Sphaerodinellopsis multilobe and Globigerinoides ruber. Benthic foraminifera dominated by Lenticulina suborbicularis, Nouvigerina ampulaceae, Cibicides tenuimargo, Anomalinoides globulosus, Heterolepa praecincta, Ammonia convexa reflects a shallow marine bathymetry zone or mid neritic (50-100m). Based on the content of planktonic and bentonic foraminifera, the sandstone units of the Bentang Formation were deposited during the Middle Miocene (N12-N13) age in a shallow marine depositional environment. Keywords: Foraminifera, Sandstone Unit, Bentang Formation, Pangandaran Introduction Marine sediments can reconstruct paleoecological parameters such as sea surface temperature, water chemical composition, biomass information, variations in geomagnetic areas, sea level, precipitation, and solar activity, by utilizing proxies contained therein (Meissner, 2007; Bradley, 2015). Foraminifera is a single celled microorganism or protist that has a shell with its life strongly influenced by various environmental factors so that it can be used as an indicator of environmental change and is a potential proxy for paleoecological, paleoclimatological and paleoseanographic research (Pringgoprawir, 1984; Saraswat, 2015). Foraminifera consists of benthic foraminifera and planktonic foraminifera. Benthic foraminifera can be found in abundance in sediment deposits and have properties that greatly affect the environment in which they live, such as brightness, pH, turbidity, salinity, oxygen levels and depth (Boltovskoy and Wright, 1976; Gustiani et al, 2015), so that they can determine the environment of deposition. Meanwhile, planktonic foraminifera has a small number of general but has a very large number of species by way of life floating on the surface and is widespread so that when planktonic foraminifera die, it will be deposited and spread widely so that it can determine its age. Based on the geographical location and regional geology, the location of the study area is included in the Middle Miocene to Early Pliocene age range with a shallow to open ocean depositional environment with a thickness of approximately 300 meters (Supriatna, et al, 1992). The Bentang Formation is composed lithology of limestone sandstone lithology, tuff sandstones, shale inserts and limestone lenses.