Abstract:

Short-lived Radioisotope (SLRad) data were generated for selected core sub-samples at 2mm sampling intervals for “surficial unit” and 5mm sampling resolution intervals to base of cores. SLRad data generated include sample activity as disintegrations per minute per gram (dpm/g) of: 1) Excess 234Th (234Thxs) activity, which is calculated by measuring the total 234Th (234ThTot) activity and the subtraction of the measured or estimated “Supported” 234Th (234ThSup) activity, 2) Excess 210Pb (210Pbxs) activity, which is calculated by measuring the total 210Pb (210PbTot) activity and subtraction of the measured background 210Pb (210PbSup) activity (average of 214Pb at 295keV, 214Pb at 351keV, and 214Bi at 609keV), 3) 137Cs activity, and 4) 7Be activity. Where appropriate, age dating was calculated in calendar years for 234Th and 210Pb activity profiles and mass accumulation rates (MAR) expressed as g/cm2/yr using the Constant Rate of Supply model. This dataset supports the publication: Larson, R. A., Brooks, G. R., Schwing, P. T., Holmes, C. W., Carter, S. R., & Hollander, D. J. (2018). High-resolution investigation of event driven sedimentation: Northeastern Gulf of Mexico. Anthropocene, 24, 40–50. doi:10.1016/j.ancene.2018.11.002

Suggested Citation:

Brooks, Gregg R., and Larson, Rebekka A.. 2018. Short-lived radioisotope geochronology from sediment cores collected during R/V Weatherbird II cruises in the northern Gulf of Mexico from 2010-11-18 to 2016-09-09. Distributed by: Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC), Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7610XTJ

Publications:

Larson, R. A., Brooks, G. R., Schwing, P. T., Holmes, C. W., Carter, S. R., & Hollander, D. J. (2018). High-resolution investigation of event driven sedimentation: Northeastern Gulf of Mexico. Anthropocene, 24, 40–50. doi:10.1016/j.ancene.2018.11.002

Larson, R. A., Brooks, G. R., Schwing, P. T., Diercks, A. R., Holmes, C. W., Chanton, J. P., … Hollander, D. J. (2019). Characterization of the Sedimentation Associated with the Deepwater Horizon Blowout: Depositional Pulse, Initial Response, and Stabilization. Deep Oil Spills, 235–252. doi:10.1007/978-3-030-11605-7_14

Brooks, G. R., Larson, R. A., Schwing, P. T., Diercks, A. R., Armenteros, M., Diaz-Asencio, M., … Hollander, D. J. (2019). Gulf of Mexico (GoM) Bottom Sediments and Depositional Processes: A Baseline for Future Oil Spills. Scenarios and Responses to Future Deep Oil Spills, 75–95. doi:10.1007/978-3-030-12963-7_5

Purpose:

Provide age control for sediment cores as well as mass accumulation rates (MAR) and inventories to assess depositional patterns and variability over past ~100 years and following the Deepwater Horizon (DWH) event.

Data Parameters and Units:

Latitude of core site (decimal degrees) Longitude of core site (decimal degrees) Water depth of core site in meters (m) Core collection Date (MM/DD/YYYY) Site Identification (ID) Core Identification (ID) Top Depth of Interval in millimeters (mm) Bottom Depth of Interval in millimeters (mm) Average Depth of Interval in millimeters (mm), average of Top and Bottom Depths 210Pb (Lead) Total (dpm/g) 210Pb (Lead) Total error (dpm/g) 234Th (Thorium) Total (dpm/g) 234Th (Thorium) Total error (dpm/g) 137Cs (Caesium) Activity (dpm/g) 137Cs (Caesium) Activity error (dpm/g) 7Be (Beryllium) Activity (dpm/g) 7Be (Beryllium) Activity error (dpm/g) 214Pb Activity (dpm/g) 214Pb Activity error (dpm/g) 214Bi (Bismuth) Activity (dpm/g) 214Bi (Bismuth) Activity error (dpm/g) 210Pb Sup Activity (dpm/g) 210Pb Sup Activity error (dpm/g) 210Pb xs Activity (dpm/g) 210Pb xs Activity error (dpm/g) Decay Corrected 210Pb xs Activity (dpm/g) Decay Corrected 210Pb xs Activity error (dpm/g) 234Th xs Activity (dpm/g) 234Th xs Activity error (dpm/g) Decay Corrected 234Th xs Activity (dpm/g) Decay Corrected 234Th xs Activity error (dpm/g) Year top of interval (Constant Rate of Supply - CRS) Year bottom of interval (CRS) Year error (CRS) MAR mass accumulation rates (g/cm2/yr) Laboratory/Facility analysis was performed at: Eckerd College, St. Petersburg FL. Note: Blank cell denotes analysis not performed for interval, and no data were generated; ND = Not detected, and specific parameter was below detection/measurement

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