First Appearance Datum (FAD) of planktonic foraminifera Boliella adamsii as the Pleistocene - Holocene boundary marker on the sea around Sumba Island Ryan Dwi Wahyu Ardi (a*, b), Aswan (a), Khoiril Anwar Maryunani (a), Eko Yulianto (c), Purna Sulastya Putra (a, c), Septriono Hari Nugroho (a, c)
a) Geological Engineering Study Program, Faculty of Earth Science and Technology, Institut Teknologi Bandung
Jl. Ganesha No. 10, Bandung 40132, Indonesia
*dwa.ryan[at]students.itb.ac.id
b) Agrotechnology Study Program, Faculty of Science and Technology, Universitas Nahdlatul Ulama Purwokerto
Jl. Sultan Agung No. 42, Purwokerto 53144, Indonesia
c) Research Center for Geological Disaster, National Research and Innovation Agency
Jl. Sangkuriang Kompleks LIPI Bandung 40135, Indonesia
Abstract
The expensive cost of Accelerator Mass Spectrometer radiocarbon dating (AMS 14C), the main tool for geochronology in Late Pleistocene - Holocene paleoclimate and paleoceanography study using marine sediment cores, hinders Indonesian researchers to produce competing research outputs. The first and last occurrences of foraminifera taxa which have been applied as Pleistocene - Holocene boundary markers in previous highly cited studies, indicated inconsistent ages in the Late Quaternary marine sediments of the Indonesian region. Quantitative foraminifera determination and oxygen isotope analysis of planktonic foraminifera (\(\delta^{18}\)Oc) species Globigerinoides (Gs.) ruber have been carried out on sediment core ST10 (off south Sumba) and ST14 (Sumba strait). \(\delta^{18}\)Oc Gs. ruber was correlated to Greenland Ice Core Chronology 2005 (GIC05) to determine the depth of the Pleistocene - Holocene boundary (~11650 BP) on core ST10 and ST14. Pleistocene - Holocene boundary depth on the core ST10 (30.5 cm) and ST14 (28.5 cm) are nearly coeval with the First Appearence Datum (FAD) of planktonic foraminifera Boliella adamsii, which at 34.5 cm depth in core ST10 and at 26.5 cm in core ST14. This indicated the practicality of Boliella adamsii FAD as a Pleistocene - Holocene boundary marker on the sea around Sumba, in case radiocarbon ages and proper \(\delta^{18}\)Oc data are unavailable. Further study with a similar method is needed to confirm the practicality of Boliella adamsii FAD as a Pleistocene - Holocene boundary marker in other Indonesian regions.
Keywords: biostratigraphy, marine sediment, micropaleontology, Late Quaternary
