Assessing the Reliability of Planktic Foraminifera Ba/Ca as a Proxy for Salinity off the Sunda Strait
Abstract: The Ba/Ca ratio of
planktic foraminifera carbonate serves as a new geochemical proxy for seawater
Ba/Ca and thus providing information on modern and past salinity and freshwater
discharge. In this study the applicability of Ba/Ca ratio of core-top
Globigerinoides sacculifer collected off the eastern tropical Indian Ocean
(ETIO) for paleoceanographic reconstructions was investigated. In doing so, we
conducted a series of cleaning experiments for Ba/Ca extraction by using
different reductive solutions. Our new results suggest that the Ba/Ca ratio of G.
sacculifer cannot be utilized as a tracer for modern and past salinity changes
in the ETIO region off the Sunda Strait. We suggest that the existence of
seasonal upwelling adds an additional signal to the seawater Ba/Ca in the ETIO,
and thus complicates the interpretation of G. sacculifer Ba/Ca as a freshwater
tracer. Moreover, our cleaning experiment results show that the cleaning
protocol of Mg/Ca, DTPA, and hydroxylamine can be used to extract valuable
Ba/Ca ratios from planktic foraminifera tests.
Keywords: G. sacculifer Ba/Ca,
foraminifera cleaning experiments, the Sunda Strait
Author: Riza Yuliratno
Setiawan, Anindya Wirasatriya, Hasrizal Bin Shaari, Eko Setyobudi, Faizal
Rachman
Journal Code: jpperikanangg170040
