Here, we present carbonate accumulation rates from two sites drilled in the western South Atlantic: Internation Ocean Discovery Program (IODP) Sites U1560 (Hole A) and 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 approached described in Coggon et al. (2024, doi:10.14379/iodp.proc.390393.102.2024). For Site U1560, sample ages were orbitally tuned. For Site U1583, the sample ages were astronomically tuned for the older part of the record (~13.8-23.2 Ma), whereas the ages for the youngest part of the record (~3.8-13.7 Ma) were calculated using to the shipboard age model (Coggon et al., 2024, doi:10.14379/iodp.proc.390393.107.2024) and reported according to the Geological Time Scale 2020 (Gradstein et al., 2020, doi:10.1016/C2020-1-02369-3).