This data release contains whole-rock geochemical analyses from drill cores and cuttings of pre-Middle Jurassic basement rocks that are buried beneath Coastal Plain sedimentary deposits in Florida and Alabama. The analyses were acquired to support geologic mapping and characterization of little-known coastal-plain basement rock units for topical studies as in geochronology, and applications ranging from mineral, energy, and water resources to earthquake hazards. These samples provide rare insights into deeply buried rocks that have no surface exposures and no known exposed correlates. The 70 whole-rock samples from drill cores and cuttings were selected and described by Ryan Deasy (USGS) and analyzed for major and trace elements at Activation Laboratories Ltd. (Actlabs) in Ancaster, Ontario, Canada. Analytical methods included lithium borate fusion or multiacid digestion followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) for major elements and inductively coupled plasma mass spectrometry (ICP-MS) for most trace elements. Additional analytical methods included instrumental neutron activation analysis (INAA) for other trace elements, and loss on ignition (LOI) by gravimetric methods. Sample information (location, depth, brief description, etc.) and geochemical data in comma separated values (.csv) format are accompanied by quality control (QC) data (.csv), a data dictionary (.csv), and metadata (.xml). Mineral abundances, determined by application of the Rietveld method to whole-rock powder X-ray diffraction data, of many of the same samples are available in a companion data release (Deasy and others, 2024a). Photographs and photomicrographs of all samples are presented in another companion data release (Deasy and others, 2024b). These data were collected to support the characterization, discrimination, and correlation of map units in the Geologic map of pre-Middle Jurassic basement rocks beneath the Coastal Plain in Florida (Deasy and others, 2024c). Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.