Data from marine sediment core MOZ4-CS09
|Author(s)||Counts John1, Jorry Stephan1, Vazquez Riveiros Natalia1, Jouet Gwenael1, Giraudeau Jacques2, Cheron Sandrine1, Boissier Audrey1, Miramontes Garcia Elda3|
|Affiliation(s)||1 : Ifremer, Unité de Géosciences Marines, Pointe du Diable, 29200, Plouzané, France
2 : UMR CNRS 5805 EPOC, Université de Bordeaux, 33615, Pessac, France
3 : Laboratoire Géosciences Océan, UMR 6538, CNRS-IUEM-UBO, 29280, Plouzané, France
|Keyword(s)||sedimentology, Quaternary, carbonate, deep marine|
A 27-meter core collected on the seafloor (1909 meters depth) near Juan de Nova island preserves a high-resolution record of carbonate export to the deep sea over the past 1 Myr. Core chronology was established using calcareous nannofossil biostratigraphy and benthic foraminiferal δ18O, which was correlated with variations in the aragonite content within seafloor muds. Throughout the core, preserved highstand intervals (MIS 1, 5, 7, 9, 11, 13, 15, 23 and 25) are marked by an increase in the aragonite content within the sediment. Aragonite is likely sourced from the nearby Juan de Nova carbonate platform ~10 km to the south, and is interpreted to result from flooding of the platform top. Platform inundation allows carbonate muds to be winnowed from their original shallow-water environment of deposition, suspended in the water column, and redeposited into the proximal slopes and basin. Sharp increases in aragonite content at the beginning of each highstand interval can be used to estimate the approximate sea level range when platform flooding occurred; results show that the depth of the platform top has likely changed little over the past 1 Myr due to balanced aggradation and subsidence. Previously hypothesized large-scale aragonite dissolution cycles are evidenced by a disproportionally low aragonite response during MIS 11. This study provides a new, exceptionally long record of highstand shedding, expanding the known occurrences of the process to the southern Indian Ocean and supporting its importance as a globally significant depositional mechanism that impacts deep-sea stratigraphic records.