Sediment analysis from IODP Hole 356-U1461C


Inorganic precipitation of aragonite is a common process within tropical carbonate environments. Across the Northwest Shelf of Australia (NWS) such precipitates were abundant in the late Pleistocene, whereas present-day sedimentation is dominated by calcitic bioclasts. This study presents sedimentological and geochemical analyses of core data retrieved from the upper 13 meters of IODP Site U1461 that provide a high-resolution sedimentary record of the last ~15 thousand years. Sediments that formed from 15 to 10.1 ka BP are aragonitic and characterised by small needles (<5 µm) and ooids. XRF elemental proxy data indicate that these sediments developed under arid conditions in which high marine alkalinity favoured carbonate precipitation. A pronounced change of XRF-proxy values around 10.1 ka BP indicates a transition to a more humid climate and elevated fluvial runoff. This climatic change coincides with a shelf-wide cessation of inorganic aragonite production and a switch to carbonate sedimentation dominated by skeletal calcite. High ocean water alkalinity due to an arid climate and low fluvial runoff therefore seems to be a prerequisite for the formation of shallow water aragonite-rich sediments on the NWS. These conditions are not necessarily synchronous to interglacial periods, but are linked to the regional hydrological cycle.

Supplement to: Hallenberger, Maximilian; Reuning, Lars; Gallagher, Stephen John; Back, Stefan; Ishiwa, Takeshige; Christensen, Beth A; Bogus, Kara A (2019): Increased fluvial runoff terminated inorganic aragonite precipitation on the Northwest Shelf of Australia during the early Holocene. Scientific Reports, 9(1)

Related Identifier
Metadata Access
Creator Hallenberger, Maximilian ORCID logo; Reuning, Lars ORCID logo; Gallagher, Stephen John ORCID logo; Back, Stefan ORCID logo; Ishiwa, Takeshige ORCID logo; Christensen, Beth A ORCID logo; Bogus, Kara A ORCID logo
Publisher PANGAEA
Publication Year 2019
Rights Creative Commons Attribution 4.0 International;
OpenAccess true
Resource Type Supplementary Publication Series of Datasets; Collection
Format application/zip
Size 4 datasets
Discipline Earth System Research
Spatial Coverage (115.066 LON, -20.214 LAT)