Trace element and isotope data measured on 36 sediments that record the opening of the south Atlantic preserved onshore, Brazil. The samples come from two main pre-salt sections within the Araripe Basin close to Juazeiro do Norte, Ceará State: the Três Irmãos quarry which records a lacustrine succession and the younger Sobradinho River Section which is a sequence of organic-rich, ostracod-bearing mudstones. Additional gypsum and ostracod samples, procured from two quarries within the Araripe Basin, were analysed to provide data from the main salt-forming interval. The samples were collected during 2023 by a team from Bristol University (Ian Parkinson, Rachel Flecker), Sao Paolo State University (Rafaela Cardoso Dantas) and University of Utrecht (Dan Palcu). The samples were analysed at Bristol University 2023-24 as part of the PhD project of Rafaela Cardoso Dantas. The aim was to use the Sr isotope and Os isotope data to reconstruct the connectivity between the global ocean and opening South Atlantic. Trace element, carbon and nitrogen analysis were analysed to help reconstruct the environmental conditions in the basin.