Abstract

This dataset includes age models, benthic foraminifera species counts used for stable isotope analysis, mass accumulation rates and volcanic grain counts from 6 sediment cores collected throughout the southern Gulf of Mexico during the R/V Justo Sierra cruise in the Southern Gulf and Ixtoc I from 2015-08-03 to 2015-08-06. Samples were analyzed by gamma spectrometry with High-Purity Germanium (HPGe) gamma-ray detectors (Canberra Coaxial Planar configuration) for total 210Pb (46.5 keV), 214Pb (295 keV and 351 keV), and 214Bi (609 keV) activities. The mean activity of the 214Pb (295 keV), 214Pb (351 keV), and 214Bi (609 keV) was used as a proxy for 226Ra activity and therefore the supported 210Pb that is produced in situ. The reported excess 210Pb (210Pbxs) is the difference of the total 210Pb and the supported 210Pb. The constant rate of supply (CRS) model was used to establish a chronology (age model) and mass accumulation rates for each core. Age model uncertainty is expressed as 1 standard deviation. Mass accumulation rates are reported as grams per square centimeter per year (g/cm2/yr). The sand-size fraction (>63μm) was isolated by wet sieving. Potential volcanic glass-rich depth intervals were selected based on age models. 100 grains of the sand fraction counted under 100x magnification. Based on this method, there is a 95% chance of finding a grain type that makes up at least 3% of the sample. Sand-sized volcanic glass grains were visually identified based on smooth texture, glassy luster, conchoidal fracture pattern and dark color. Clear volcanic glass grains were not counted in this study, as the visual differences between clear volcanic glass and immature quartz grains are difficult to discern even at high magnification. Benthic foraminifera (C. wuellerstorfi and C. pachyderma) tests were picked from each sample to obtain greater than 50g of benthic foraminifera carbonate for stable isotope analysis. The numbers of each species used for each measurement are included (p= C. pachyderma, w= C. wuellerstorfi). All data are presented with depth (mm) below the core surface. The R/V Justo Sierra-Southern Gulf & Ixtoc I cruise on 2015-07-29 to 2016-08-11 objective was to characterize the distribution and fate of oiled sediment at sites on the continental shelf and slope of the Southern Gulf of Mexico with reference to the Ixtoc blowout (1979-1980) and the chief scientist was Dr. David Hollander. CTD and trace metals in sediment cores collected during the R/V Justo Sierra cruise and coastal sampling in the southern Gulf of Mexico are available under GRIIDC UDIs R4.x267.179:0019 and R4.x267.000:0115 respectively.

Comments

Data and metadata is made available by the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC) through a CC0 license in compliance with the Gulf of Mexico Research Initiative (GoMRI). The original dataset landing pages may be accessed at GRIIDC’s dataset monitoring webpage.

Data users are encouraged to contact the originating investigator prior to data use and provide appropriate credit.

Purpose

The purpose of this study was to identify the long-term preservation of Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) associated with Ixtoc-1 using a multiproxy approach by pairing short-lived radioisotope age models and sedimentary flux measurements with organic geochemical tracers and delta13C CaCO3.

Keywords

benthic foraminifera, stable isotopes, oil spill, Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA), sediment core, mass accumulation rate, volcanic grains, sedimentary age models, constant rate of supply (CRS) model

UDI

R4.x267.000:0142

Date

11-29-2018 12:00 AM

Point of Contact

Schwing, Patrick
University of South Florida
College of Marine Science
140 7th Ave South
St. Petersburg , FL 33701
USA
pschwing@mail.usf.edu

Funding Source

RFP-IV

Start of Data Collection

8-3-2015

End of Data Collection

8-6-2015

DOI

https://doi.org/10.7266/n7-1k5d-4z68

Rights Information

Creative Commons License
This work is licensed under a Creative Commons Public Domain Dedication 1.0 License.

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