Multi-Sensor Core Logger (MSCL) data of piston and gravity cores collected in September 2019 offshore of south-central California (USGS FAN 2019-642-FA)

Piston (JPC) and gravity (GC) cores were collected at sea aboard the R/V Bold Horizon on U.S. Geological Survey (USGS) cruise 2019-642-FA in conjunction with the Monterey Bay Aquarium Research Institute (MBARI). Often, a trigger core (TC) and a jumbo piston core accompanies each other at the same site; gravity cores will not have associated trigger cores. The trigger cores provide the shallowest sedimentary record at jumbo piston core sites. The cores were cut at sea into sections of maximum 1.5 meters and transported back to the USGS Pacific Coastal and Marine Science Center in Santa Cruz, CA. In the lab, cores were run through a GeoTek Multi-Sensor Core logger (MSCL), which measures gamma density, P-wave seismic velocity, and magnetic susceptibility. Measurements were calibrated to account for changes in core diameter and temperature. Gamma density measurements were calibrated using a known standard. Data are presented in folders per core. Folders follow the naming convention ##CoreType where ## is the core site number and CoreType is either TC (trigger core), JPC (jumbo piston core), or GC (gravity core) at that core site. Core sections were most often logged in sequence from top to bottom of the core (for example, starting with section 1, the shallowest section in the core, and then logging in sequence downsection from there). This method provides a continuous downcore data file in most cases. In some cases, a section needed to be relogged due to equipment or user issues. When relogging was necessary, folders have been appended with section numbers and/or data types (for example, 17JPC_section5) indicating which sections and/or data types were relogged. These folders contain only the data for those relogged sections. Each folder contains a .csv file that includes the scanning parameters and measurements, as well as several files including the following: a .raw file (machine-readable text file) containing the raw, uncalibrated data collected by the GeoTek system; an .out file (machine-readable text file) is the lab-calibrated file (the processed data) using calibration parameters outlined in the header of the .out file (the .out file is likely to be the file of most interest to users); a GeoTek system file (.dat); and a calibration files (.cal). The .dat and .cal files can be used to open, view, and manipulate the logging data using a GeoTek software system.