This readme describes the file in the headspace gas dataset and its contents. This readme also provides references to where the data is presented in the expedition proceedings.

GOM Hydrates 23027 Headspace Samples 123023_edit.xlsx
   Gas composition of headspace gas samples analyzed at The Ohio State University. Results are presented in Site H: Figure F66 and Figure F67 (https://doi.org/10.5281/zenodo.13971276).
      File Headers (abridged):
      Tab: Gas Data Compilation
         Sample or Samples: sample name including expedition, hole, core name and coring tool, section number and piece letter, and depth in section of the sediment sample in centimeters
            H = Advanced Piston Corer
            X = Extended Core Barrel
            CS = Pressure Coring Tool in the cutting shoe configuration
            FB = Pressure Coring Tool with Ball Valve in the face bit configuration 
         Compressed sample top depth (mbsf): depth of the top of the sediment sample in the hole, calculated from the depth in section and the core top in the hole. Cores with recovery greater than 100% were compressed. See Expedition UT-GOM2-2 Methods (Flemings et al., 2025a) https://doi.org/10.5281/zenodo.13971228. Values are in meters below the seafloor.
         Compressed sample bottom (mbsf): depth of the bottom of the sediment sample in the hole, calculated from the depth in section and the core top in the hole. Cores with recovery greater than 100% were compressed. See Expedition UT-GOM2-2 Methods (Flemings et al., 2025a) https://doi.org/10.5281/zenodo.13971228. Values are in meters below the seafloor.
         H2 ccSTP/cc: cubic centimeters of hydrogen gas at standard temperature and pressure
         H2 ppm: concentration of hydrogen gas in parts per million
         H2S ccSTP/cc: cubic centimeters of hydrogen sulfide gas at standard temperature and pressure
         H2S ppm: concentration of hydrogen sulfide gas in parts per million
         CH4 ccSTP/cc: cubic centimeters of methane gas at standard temperature and pressure
         CH4 ppm: concentration of methane gas in parts per million
         C2H6 ccSTP/cc: cubic centimeters of ethane gas at standard temperature and pressure
         C2H6 ppm: concentration of ethane gas in parts per million
         C3 ccSTP/cc: cubic centimeters of propane gas at standard temperature and pressure
         C3 ppm: concentration of propane gas in parts per million
         iC-4 ccSTP/cc: cubic centimeters of butane gases at standard temperature and pressure
         nC-4 ppm: concentration of butane gases in parts per million
         iC-5 ccSTP/cc: cubic centimeters of pentane gases at standard temperature and pressure
         nC-5 ppm: concentration of pentane gases in parts per million
         C-6  ccSTP/cc: cubic centimeters of hexane gases at standard temperature and pressure
         N2 ccSTP/cc: cubic centimeters of nitrogen gas at standard temperature and pressure
         N2 ppm:
         O2 ccSTP/cc: cubic centimeters of oxygen gas at standard temperature and pressure
         O2 ppm:
         CO2 ccSTP/cc: cubic centimeters of carbon dioxide gas at standard temperature and pressure
         CO2 ppm:
         Ar ccSTP/cc: cubic centimeters of argon gas at standard temperature and pressure
         Ar ppm:
         He ccSTP/cc: cubic centimeters of helium gas at standard temperature and pressure
         He ppm:
         TOTAL: cubic centimeters of all gases measured
         GROSS BTU (BEFORE CO2 REMOVAL):	total potential heat output before carbon dioxide removal in British Thermal Units
         NET BTU (BEFORE CO2 REMOVAL): total potential heat output less heat losses within the system before carbon dioxide removal in British Thermal Units
         GROSS BTU (AFTER CO2 REMOVAL): total potential heat output after carbon dioxide removal in British Thermal Units
         NET BTU (AFTER CO2 REMOVAL): total potential heat output less heat losses within the system after carbon dioxide removal in British Thermal Units
         CH4/ 4He: ratio of methane to helium 4
         CH4/ Ar: ratio of methane to argon
         N2/ Ar: ratio of nitrogen to argon
         CH4/ C2H6+: ratio of methane to all other hydrocarbons
         CH4/ CO2: ratio of methane to carbon dioxide