Download URLhttps://www.bco-dmo.org/dataset/784204/data/download
Media Typetext/tab-separated-values
CreatedDecember 12, 2019
ModifiedFebruary 11, 2020
StateFinal no updates expected
Brief DescriptionPorewater Si concentrations from sediment cores P3,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.

Filtered but unamended porewater samples, stored at 4°C, were used for quantifying multiple stable ions, including silicate, by ion chromatography at GEOMAR, Kiel, Germany (Hensen et al., 2007).

Processing Description

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


Ion chromatography is a form of liquid chromatography that measures concentrations of ionic species by separating them based on their interaction with a resin. Ionic species separate differently depending on species type and size. Ion chromatographs are able to measure concentrations of major anions, such as fluoride, chloride, nitrate, nitrite, and sulfate, as well as major cations such as lithium, sodium, ammonium, potassium, calcium, and magnesium in the parts-per-billion (ppb) range. (from http://serc.carleton.edu/microbelife/research_methods/biogeochemical/ic.html)


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).

Si [Si]
Si concentration

Si (Silicon) concentration. May be reported in parts per million, nanomoles/Liter, or other units. Refer to dataset metadata for units.

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