Miocene Planktonic Foraminifera of Calcareous Sandstone Unit in Pamutuan Formation West Java, Indonesia

Abstract

The research area is located in Cigugur, Jadimulya, and Bangunkarya, Pangandaran, West
Java. This research is focus on identification and determination the age of calcareous sandstone unit
based on foraminifera assemblages. In the research area, the calcareous sandstone unit included in
Pamutuan Formation. Based on previous research, regionally the age of Pamutuan Formation is
Middle Miocene which deposited with many energy changes and related to the effect of sea level
changes. The research method started with literature study followed by field observation by using
spotting sampling method, preparation process, and laboratory analysis. Preparation process of
foraminifera planktonic performed against six samples of rock by using the method of residues.
Samples of foraminifera planktonic are analyzed using binocular microscope and determining the
age range of the foraminifera planktonic species based on Bolli classification. The calcareous
sandstone unit consists of massive sandstones. The foraminifera planktonic such as Globorotalia
opima nana, Catappsydrax dissimilis, Globorotalia obesa, Globigerinoides ruber, Globorotalia
mayeri, Sphaerodinellopsis disjuncta, Globigerinoides obliquus, and Globorotalia fohsi
peripheroronda are identified in samples. Based on the presence of those foraminifera planktonic
marker species, conclude that the calcareous sandstone unit in Pamutuan Formation is indicated to be
deposited in the relative age range of N6 to N10 or Early Miocene to Middle Miocene.