Proxy dataset of coastal California hydroclimate response to the Paleocene-Eocene Thermal Maximum

To constrain the regional hydroclimate response along the central California coast during the Paleocene-Eocene Thermal Maximum (PETM), several observational datasets were collected and analyzed. These records are either directly or indirectly sensitive to hydroclimate shifts. The study area, Lodo Gulch, is part of the late Paleocene-early Eocene Lodo Formation located in the Panoche Hill of central California. 27 sediment samples collected from the Lodo Formation were analyzed for organic C isotopic stratigraphy (δ13Corg) to establish the pre-PETM baseline. These samples were measured at the UCSC Stable Isotope Laboratory using an elemental analyzer coupled with the isotope ratio mass spectrometer. Grain size distribution was used to qualitatively assess relative variations in sediment transport (i.e. fluvial activity) and to constrain hydroclimate influences from local sea level change during the PETM. 39 grain size samples were analyzed by laser diffraction with Polarization Intensity Differential Scatter (PIDS). Additionally, 38 clay assemblage samples from the Lodo Formation were measured to assess regional hydroclimate conditions using an X-ray diffraction instrument at UCSC. Clay species (i.e., Smectite, Ilite, Kaolinite, Chlorite) were identified based on peak positions and intensities representing each clay mineral. Leaf wax n-alkane stable isotope records were also analyzed to constrain local/regional precipitation patterns. 59 samples were processed on gas chromatograph (GC) coupled with isotope ratio mass spectrometer for δ13C and δ2H.