Download URLhttps://www.bco-dmo.org/dataset/661658/data/download
Media Typetext/tab-separated-values
CreatedOctober 14, 2016
ModifiedDecember 5, 2017
StateFinal no updates expected
Brief DescriptionPorewater DIC concentrations and d13C isotopic values from sediment cores collected on the Guaymas Basin Ridge flanks and the Sonora Margin in 2014

Acquisition Description

2 ml porewater samples were filtered through 0.22 um filters to remove particles, and injected 30 ml serum vials that were closed with thick rubber stoppers. The samples were stored frozen at -20 C. DIC analysis was performed in the lab of J.P. Chanton (Florida State University); briefly, the samples were acidified with phosphoric acid, and measured by GC-IRMS as described (Chanton et al. 2012).

Chanton, J.P., J. Cherrier, R.M. Wilson, J. Sarkodee-Adoo, S. Bosman, A. Mickle, and W.M. Graham. 2012. Radiocarbon evidence that carbon from the Deepwater Horizon spill entered the planktonic food web of the Gulf of Mexico. Environmental Research Letters 7, 045303. doi:10.1088/1748-9326/7/4/045303

Processing Description

BCO-DMO Processing:
- created a column for core number;
- added lat, lon, and depth for each core from the metadata form;
- modified parameter names to conform with BCO-DMO naming conventions.


Instance Description (GC-IRMS)
Samples for DIC analysis were acidified with phosphoric acid, and measured by GC-IRMS as described (Chanton et al. 2012).
The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).


core [core_id]

Core identifier

core number/identification, to be used with ice, rock and sediment cores

lat [latitude]
Latitude of sampling location; postive = north

latitude, in decimal degrees, North is positive, negative denotes South; Reported in some datasets as degrees, minutes

lon [longitude]
Longitude of sampling location; negative = west

longitude, in decimal degrees, East is positive, negative denotes West; Reported in some datsets as degrees, minutes

depth [depth_w]

Water depth at sampling location

water depth, in meters

core_sample [sample]

Identifier for the core sample

unique sample identification or number; any combination of alpha numeric characters; precise definition is file dependent

actual_depth [depth_core]

Sample depth, within the core

depth in core; mid-point of interval sampled

Dissolved inorganic carbon concentration

Dissolved Inorganic Carbon

DIC_d13C [d13C_DIC]

DIC d13C signature

Stable carbon isotope ratio of dissolved inorganic carbon (13C/12C ratio in DIC).

Dataset Maintainers

Andreas P. TeskeUniversity of North Carolina at Chapel Hill (UNC-Chapel Hill)
Ivano AielloMoss Landing Marine Laboratories (MLML)
Ana Christina RaveloUniversity of California-Santa Cruz (UC Santa Cruz)
Andreas P. TeskeUniversity of North Carolina at Chapel Hill (UNC-Chapel Hill)
Shannon RauchWoods Hole Oceanographic Institution (WHOI BCO-DMO)

BCO-DMO Project Info

Project TitleRAPID proposal: Site characterization cruise to document the active and extensive subsurface biosphere in the Guaymas Basin
AcronymRAPID Guaymas Basin
CreatedNovember 5, 2015
ModifiedMarch 13, 2019
Project Description

Description from NSF project abstract:
The Guaymas Basin in the central Gulf of California is an active tectonic spreading center overlain with thick, organic-rich sediments. In contrast to typical deep-water, mid-ocean ridge spreading centers that have very focused magmatism and little or no sediment, magmatism in the Guaymas Basis is more broadly distributed. This broadly-distributed magmatism significantly expands the fraction of organic-rich sediments that may be subject to alteration by the magmatic heat and thus it greatly expands the range of environments that support hydrocarbon generation and microbial populations in the sediments. Recognition that magmatism is not confined to the spreading axis, but instead is distributed throughout Guaymas Basin, suggests that models for the natural sequestration of carbon, the formation of oceanic crust, and life in the subsurface in marginal rift basins should be reconsidered as this has implications for the long-term removal of atmospheric carbon dioxide (and hence potential climatic implications). The Principal Investigator of this RAPID proposal is a lead proponent on an International Ocean Discovery Program (IODP) proposal to study this system in depth through scientific ocean drilling. To properly plan this expensive IODP expedition, additional site characterization gained from sediment sampling and seismic data is required. This proposal requests funds for the Principal Investigator to participate on an already planned site survey cruise aboard the Mexican Research Vessel (RV) El Puma. The results from this cruise will provide valuable data, at an exceptionally low investment, to guide decisions about potential future scientific drilling in the Guaymas Basin.

This RAPID proposal requests funds for the Principal Investigator to participate on a Mexican site survey cruise in October 2014 on RV El Puma to collect five-meter gravity cores of an extensive sediment transect across the Guaymas Basin and to integrate sequencing-based microbial community analyses of subsurface bacteria and archaea with biogechemical characterizations of these subsurface sediments. Gravity coring and microbial community analysis will target cold non-hydrothermal sediments as well as off-axis hydrothermally-influenced sediments. The gravity coring campaign and the geochemistry/microbiology studies are coordinated with heatflow measurements and extensive 2D seismic analysis and high-resolution 3D seismic mapping by other planned Mexican and German cruises. This multi-pronged strategy will deliver the additional data and complete the site characterizations that are required to properly plan a potential IODP drilling expedition by the JOIDES Resolution.

Project Maintainers
Andreas P. TeskeUniversity of North Carolina at Chapel Hill (UNC-Chapel Hill)Principal Investigator