Drilling operations and initial results of the Trans-Amazon Drilling Project (TADP)

The Trans-Amazon Drilling Project (TADP) aims to reconstruct the Amazonian physical landscape, climate, and rivers during the Cenozoic, in parallel with the evolutionary history of the tropical forests. Scientific drilling was carried out in the western Acre Basin and the eastern Marajó Basin to recover Cenozoic sediments up to 2000 m and 1280 m depth, respectively. Multiple episodes of drill-string imprisonment hindered the achievement of target depths, none-the-less the TADP recovered an 870-m drill core (TADP-1A) in the Acre Basin (923 m depth) and a 735-m drill core (TADP-2A) in the Marajó Basin (924 depth) between June 2023 and September 2024. Each core comprises a sequence of poorly consolidated sandstones, siltstones, and mudstones representing Amazonian fluvial sedimentation during the Late Cenozoic. Sandstones and mudstones, respectively, of the Acre Basin are distinctive in their immature feldspathic composition and intense paleopedogenesis in comparison with analogous facies of the Marajó Basin. The TADP-1A core was described and sub-sampled for laboratory analyses, whereas the detailed description and sub-sampling of the TADP-2A core is scheduled for July 2026. This presentation will describe drilling operational issues, outreach activities, and initial results from ongoing geochronologic, geochemical, mineralogical, geophysical, and biotic analyses of the TADP-1A core.