Ferromanganese crust and phosphorite minerals were collected using remotely operated vehicles in the Southern California Borderland during two separate research cruises – NOAA Ocean Exploration Trust cruise NA124 onboard the E/V Nautilus in 2020, and Schmidt Ocean Institute cruise FK210726 onboard the R/V Falkor in 2021. Ferromanganese crust and phosphorite samples were described and subsampled for geochemical analysis at the USGS Pacific Coastal and Marine Science Center. Geochemical analyses were completed by outside commercial laboratories, and the results were provided to the USGS. Geochemical data, bulk and layer thickness information, as well as location information (latitude, longitude, depth) for each sample are provided here. The geochemical Borderland work was funded by the Pacific Coastal and Marine Science Center and ship time was funded by NOAA Office of Ocean Exploration and Research (grant number NA19OAR110305).