Miocene to Early Pliocene carbonate accumulation rates from the western South Atlantic, IODP Site 393-U1583

Here, we present carbonate accumulation rates from a site drilled in the western South Atlantic, Internation Ocean Discovery Program (IODP) Site U1583 (Hole C). Carbonate accumulation rates were calculated by multiplying calcium carbonate weight percent with mass accumulation rates. Calcium carbonate weight percent was measured at the Lamont-Doherty Earth Observatory of Columbia University (New York, NY) using an UIC inc. CM5012 CO2 coulometer with an Automate FX Inc. automated sample acidification and delivery carousel. For the analysis, a carbonate standard was used (GFS Chemicals Calcium Carbonate Standard - ACS). Mass accumulation rates were calculated as the product of linear sedimentation rate and dry bulk density, which was determined using the approach described in Coggon et al. (2024, doi:10.14379/iodp.proc.390393.102.2024). For the older part of the record (~13.8-23.2 Ma), sample ages were orbitally tuned using the Laskar 2010 solution (Laskar et al., 2011, doi:10.1051/0004-6361/201116836) and agree with the Geological Time Scale 2020 (Gradstein et al., 2020, doi:10.1016/C2020-1-02369-3). For the youngest part of the record (~3.8-13.7 Ma), sample ages were calculated using to the shipboard age model (Teagle et al., 2024, doi:10.14379/iodp.proc.390393.107.2024) and reported according to the GTS 2020.