Abstract:

This dataset contains Isotopic composition (13C and 14C) of sedimentary organic carbon within sediments collected aboard R/V Weatherbird II (WB1701, WB1603) and R/V Justo Sierra (JS0815) cruises in the southern Gulf of Mexico from 2011-08-03 to 2016-08-30. The data from 2015 are inclusive of data available under GRIIDC Unique Dataset Identifier (UDI) R4.x267.000:0005 (doi: 10.7266/N7SN0700) with additional analysis such as the age based on ^14^C. The dataset also includes the sample collection date, location, and depth of water. Finnigan DELTAplus XP by Thermo Fisher Scientific was used to determine the stable isotopes of carbon and nitrogen.

Suggested Citation:

Chanton, Jeffrey. 2021. Isotopic composition (13C and 14C) of sedimentary organic carbon within sediments collected aboard multiple research cruises in the southern Gulf of Mexico from 2011-08-03 to 2016-08-30. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/n7-4bfp-5182

Purpose:

To examine sediments for the preservation of a Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) event and to determine a baseline isoscape for the southern Gulf of Mexico.

Data Parameters and Units:

Label; Cruise ID; Collection Date (MM/DD/YYYY); LAT (Latitude, decimal degrees); LON (Longitude, decimal degrees); depth (depth of water in meters); d13C (carbon isotopic composition of the organic matter); d15N (15N isotopic composition of the organic matter); %C (the % carbon by weight); %N (the % nitrogen by weight); ID (Sample ID); D14C (the radiocarbon content in DELTA 14C units); NOSAMS (National Ocean Sciences Accelerator Mass Spectrometry) - Accession #, Receipt #, F Modern (Fraction modern), Fm Err (Fraction modern error), Age, Age Err (Age error), d13C; UGAMS (The University of Georgia Center for Applied Isotope Studies) - UGAMS #, 14C age, years BP, pMC (percent modern carbon); Sample equipment (multicore or shipex (grab sampler)). Please note empty cells mean "No Data." The dataset also includes the cruise documentation for the R/V Justo Sierra cruise (JS0815, 2015-07-29 to 2015-08-11) led by chief scientists Dr. David Hollander and Dr. Patrick Schwing, and the R/V Weatherbird II cruises (WB1701, 2016-08-02 to 2016-09-09; and WB1603, 2015-09-10 to 2015-10-02) led by chief scientist Dr. Steven Murawski. Please note that the samples for 2011 were collected by another researcher and the cruise information is not available. The cruise ID (Column B) in the file "Data file grid C southern Gulf (9-13-2019) rev 1_22_20 (ID fixed)", rows 323-360, refers to ID as samples were labeled. For example: WB0816 is how the samples were labeled as they were collected on the Weatherbird (WB) in August of 2016 but they were collected during R/V Weatherbird II cruise WB1701; similarly, WB0915 is how the samples were labeled as they were collected on the Weatherbird (WB) in September of 2015 but they were collected during R/V Weatherbird II cruise WB1603.

Methods:

Carbon and nitrogen isotopes and concentrations in % were determined on a Carlo-Erba elemental analyzer at the Stable Isotope Laboratory at Duke University. Sediment samples for C-14 were combusted at the National High Magnetic Field laboratory by use of a muffle furnace at 850°C for four hours and then they were collected in the form of pure CO2 by use of a vacuum line series of cold traps to remove water vapor and non-condensable gases. Purified samples were shipped to the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility or the University of Georgia (UGA) where the samples were prepared as graphic targets and analyzed by accelerator mass spectrometry.

Instruments:

Finnigan DELTAplus XP by Thermo Fisher Scientific was used to determine the stable isotopes of carbon and nitrogen.

Individual Files: