URLhttps://www.bco-dmo.org/dataset/763715
Download URLhttps://www.bco-dmo.org/dataset/763715/data/download
Media Type text/tab-separated-values
Created March 27, 2019
Modified June 4, 2019
State Final no updates expected
Brief Description

d13C and d18O isotopic data for carbonate nodules and sedimentary carbonates in Guaymas Basin and Sonora Margin sediments

Acquisition Description

Sediment cores were obtained by Piston coring (using commercial PVC core liners) onboard R/V El Puma. Samples selected for carbonate isotope analyses were freeze-dried, homogenized, and roasted under vacuum to eliminate organic matter. Isotope analyses was performed on ~500 µg of sediment using a Kiel devise coupled with a Thermo MAT 253 gas ratio mass spectrometer at the University of California, Santa Cruz. Values are reported in the per mil (‰) notation relative to Vienna Pee Dee Belemnite (VPDB). Reproducibility of in-house standards is 0.07‰ for 18O and 0.03‰ for 13C.

Processing Description

BCO-DMO Processing:
– modified column headers (replaced spaces with underscores, renamed standard deviation columns for clarity);
– replaced “n.d.” with “nd” (“no data”).

Instruments

Details
Instance Description (Thermo MAT 253)

Isotope analyses was performed on ~500 µg of sediment using a Kiel devise coupled with a Thermo MAT 253 gas ratio mass spectrometer at the University of California, Santa Cruz.

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).
The piston corer is a type of bottom sediment sampling device. A long, heavy tube is plunged into the seafloor to extract samples of mud sediment. A piston corer uses a "free fall" of the coring rig to achieve a greater initial force on impact than gravity coring. A sliding piston inside the core barrel reduces inside wall friction with the sediment and helps to evacuate displaced water from the top of the corer. A piston corer is capable of extracting core samples up to 90 feet in length.

Parameters

Core_section_cm [sample]
Details
Core_section_cm
Sample identification (core number, section number, cm within section)

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

cm_in_core [depth_core]
Details
cm_in_core
Total sediment depth in centimeters
depth in core; mid-point of interval sampled
sample_type [sample_type]
Details
sample_type
Description of sample type
text description of type of sample collected (rock, bio, fluid, etc)
d13C [d13C]
Details
d13C
d13C stable isotope values reported in per mil (‰) notation relative to Vienna Pee Dee Belemnite (VPDB)

Delta 13C (d13C) is the ratio of stable isotopes 13C:12C, reported in parts per thousand (per mil, 0/00).

d13C_stdev [d13C]
Details
d13C_stdev
Standard deviation of d13C

Delta 13C (d13C) is the ratio of stable isotopes 13C:12C, reported in parts per thousand (per mil, 0/00).

d18O [delta18O]
Details
d18O
d18O stable isotope values reported in per mil (‰) notation relative to Vienna Pee Dee Belemnite (VPDB)
CAUTION file dependent; ratio oxygen 16 to oxygen 18 corrected to PDB standard; delta 18O are for the oxygen in CO2 converted from DIC
d18O_stdev [delta18O]
Details
d18O_stdev
Standard deviation of d18O
CAUTION file dependent; ratio oxygen 16 to oxygen 18 corrected to PDB standard; delta 18O are for the oxygen in CO2 converted from DIC

Dataset Maintainers

NameAffiliationContact
Andreas P. TeskeUniversity of North Carolina at Chapel Hill (UNC-Chapel Hill)
Ana Christina RaveloUniversity of North Carolina at Chapel Hill (UNC-Chapel Hill)
Shannon RauchUniversity of California-Santa Cruz (UC Santa Cruz)

BCO-DMO Project Info

Project Title RAPID proposal: Site characterization cruise to document the active and extensive subsurface biosphere in the Guaymas Basin
Acronym RAPID Guaymas Basin
URLhttps://www.bco-dmo.org/project/626087
Created November 5, 2015
Modified March 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.

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