Abstract:

This dataset contains short-lived radioisotope (SLRad) data collected aboard R/V Justo Sierra cruise JS-0815 in the southern Gulf of Mexico from 2015-07-31 to 2015-08-08. SLRad data were generated for selected core sub-samples at 2mm sampling intervals for “surficial unit” and 5mm sampling resolution intervals to the base of cores. SLRad data generated include sample activity as disintegrations per minute per gram (dpm/g) of 1) Excess Thorium-234 (234Thxs) activity, which is calculated by measuring the total Thorium-234 (234ThTot) activity and the subtraction of the measured or estimated “supported” Thorium-234 (234ThSup) activity, 2) Excess Lead-210 (210Pbxs) activity, which is calculated by measuring the total Lead-210 (210PbTot) activity and subtraction of the measured background "supported" Lead-210 (210PbSup) activity {average of Lead-214 (214Pb) at 295 kiloelectron volts (keV), 214Pb at 351keV, and Bismuth-214 (214Bi) at 609keV}, 3) Cesium-137 (137Cs) activity, and 4) Berilium-7 (7Be) activity. The cruise documentation was provided for the R/V Justo Sierra cruise JS-0815. The cruise was led by chief scientist Dr. David Hollander.

Suggested Citation:

Gregg Brooks and Rebekka Larson. 2019. Short-lived radioisotope (SLRad) data collected aboard R/V Justo Sierra cruise JS-0815 in the southern Gulf of Mexico from 2015-07-31 to 2015-08-08. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-jm62-5b12

Publications:

Schwing, P. T., Hollander, D. J., Brooks, G. R., Larson, R. A., Hastings, D. W., Chanton, J. P., … Langenhoff, A. (2019). The Sedimentary Record of MOSSFA Events in the Gulf of Mexico: A Comparison of the Deepwater Horizon (2010) and Ixtoc 1 (1979) Oil Spills. Deep Oil Spills, 221–234. doi:10.1007/978-3-030-11605-7_13

Schwing, P. T., Machain-Castillo, M. L., Brooks, G. R., Larson, R. A., Fillingham, J. N., Sanchez-Cabeza, J. A., … Hollander, D. J. (2021). Multi-proxy assessment of recent regional-scale events recorded in Southern Gulf of Mexico sediments. Marine Geology, 434, 106434. doi:10.1016/j.margeo.2021.106434

Purpose:

Provide age control and sedimentation rates for sediment cores

Data Parameters and Units:

Water depth of core site (m), core collection date (MM/DD/YYYY), site identification (ID), sediment core identification (ID), top depth of interval (mm), bottom depth of interval (mm), average depth of interval (mm), 210Pb (Lead) total (dpm/g), 210Pb (Lead) total error (dpm/g), 234Th (Thorium) Total (dpm/g), 234Th (Thorium) error (dpm/g), re-Analysis of 234Th (Thorium) activity (dpm/g) represent 234ThSup (“supported” Thorium), re-Analysis of 234Th (Thorium) activity error (dpm/g) represent 234ThSup (“supported” Thorium), 137Cs (Caesium) activity (dpm/g), 137Cs (Caesium) activity error (dpm/g), 7Be (Beryllium) activity (dpm/g), 7Be (Beryllium) activity error (dpm/g), 214Pb (Lead, 295 keV) activity (dpm/g), 214Pb (Lead, 295 keV) activity error (dpm/g), 214Pb (Lead, 351 keV) activity (dpm/g), 214Pb (Lead, 351 keV) activity error (dpm/g), 214Bi (Bismuth) activity (dpm/g), 214Bi (Bismuth) activity error (dpm/g), 210PbSup (“supported” Lead) activity (dpm/g), 210PbSup (“supported” Lead) activity error (dpm/g), 210Pbxs (Excess Lead) activity (dpm/g), 210Pbxs (Excess Lead) activity error (dpm/g), decay corrected 210Pbxs (Excess Lead) activity (dpm/g), decay corrected 210Pbxs (Excess Lead) activity error (dpm/g), 234Thxs (Excess Thorium) activity (dpm/g), 234Thxs (Excess Thorium) activity error (dpm/g), decay corrected 234Thxs (Excess Thorium) activity (dpm/g), decay corrected 234Thxs (Excess Thorium) activity error (dpm/g), laboratory/facility where analysis was performed: Eckerd College, St. Petersburg, Florida. Blank cell denotes no analysis performed.

Methods:

The cores were extruded in the laboratory and the sediment core preservation was not required for this analysis. Samples were analyzed for short-lived radioisotopes by gamma spectrometry on Series HPGe (High-Purity Germanium) Coaxial Planar Photon Detectors. The detail methods on short-lived radioisotope geochronology can be found at Larson et al., 2018.

Instruments:

Series HPGe (High-Purity Germanium) Coaxial Planar Photon Detectors.

Provenance and Historical References:

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

Individual Files: