Download URLhttps://www.bco-dmo.org/dataset/784248/data/download
Media Typetext/tab-separated-values
CreatedDecember 12, 2019
ModifiedFebruary 11, 2020
StateFinal no updates expected
Brief Descriptiondelta 15N values from sediment cores P6, P10, P11, P12, and P13, collected on the Guaymas Basin Ridge flanks and the Sonora Margin

Acquisition Description

All coring operations were performed using a the piston-coring system onboard the R/V El Puma. See http://www.buques.unam.mx for additional information.

Bulk sediment δ¹⁵N and elemental ratio data were collected using 20mg samples in Sn capsules; organic δ¹³C and elemental composition data were collected using 2.5mg samples of acidified sediment in Sn capsules. All samples were measured by Dumas combustion performed on a Carlo Erba 1108 elemental analyzer coupled to a ThermoFinnigan Delt Plus XP isotope ratio mass spectrometer (EA-IRMS). An in-house gelatin standard, Acetanilide, and an in-house bulk sediment standard, "Monterey Bay Sediment Standard", were used in all runs. Reproducibility of an in-house matrix-matched sediment standard is <0.1‰ VPDB for δ¹³C and <0.2‰ AIR for δ¹⁵N. Data is corrected for blank, and for drift when appropriate. Carbon and nitrogen elemental composition was estimated based on standards of known composition, for which analytical precision is determined to be better than 1%.

Processing Description

BCO-DMO Processing:
- modified parameter names (removed units in parens);
- added dates provided by submitter.


Carlo Erba 1108 elemental analyzer [Elemental Analyzer]

Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material.

ThermoFinnigan Delt Plus XP isotope ratio mass spectrometer (EA-IRMS) [Isotope-ratio Mass Spectrometer]
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

depth_water [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

depth_cmbsf [depth_bsf]
Depth in centimeters below seafloor

depth below seafloor.  Includes mbsf (meters below seafloor) and cmbsf (centimeters below seafloor).

Orgmatter_del15N [d15N]

del15N values for organic matter

delta 15N (d15N) is a measure of the ratio of stable isotopes 15N:14N.  It is commonly reported in parts per thousand (per mil, 0/00).

date [date]

Sample date. Format: yyyy-mm-dd

date; generally reported in GMT as YYYYMMDD (year; month; day); also as MMDD (month; day); EqPac dates are local Hawaii time. ISO_Date format is YYYY-MM-DD (http://www.iso.org/iso/home/standards/iso8601.htm)

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)
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