Project: The Dorado Outcrop low-temperature ridge flank environment

Acronym/Short Name: 
Dorado ridge flank environment
Start Date: 
2012-12
End Date: 
2014-12
Geolocation: 
Seafloor basalts from Dorado Outcrop 9N 87 W
Programs: 

  Center for Dark Energy Biosphere Investigations [C-DEBI]

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Description

Project description obtained from C-DEBI: 
With support from this project, I participated in two research cruises to the Dorado Outcrop in 2013 and 2014, leading efforts to collect samples of fluids, rocks, and sediment for microbiological characterization. In 2013, we were successful in discovering low-temperature seeps on the outcrop, although sampling issues prevented the collection of pristine fluid samples for detailed microbiological characterization. High-quality fluids were collected during the 2014 cruise, and several C-DEBI student and postdoc collaborators that participated in the 2014 cruise are currently analyzing them. We collected seafloor basalts from around the outcrop, both near and far to active venting. A student is currently analyzing 16S rRNA gene sequence libraries from these samples; preliminary analysis indicates some microbial community overlap with seafloor basalts from other deep-sea environments, but also some unique groups that may reflect the age of the Dorado Outcrop environment compared to other studies. We collected push cores and gravity cores during both cruises to document the diffusion of potentially altered basement fluids into sediment, and were successful in documenting the presence of oxygen in these cores, confirming our hypotheses about fluid-rock reactions in basement surrounding Dorado Outcrop. Several C-DEBI supported students and postdocs are further characterizing the sediment biogeochemistry and microbial community activity, structure and function. Both cruises were used as opportunities to engage the general public in deep-sea science through news articles, microblogging, and a feature on Al Jazeera America.

Related Publications:
Lee, M.D., Walworth, N.G., Sylvan, J.B., Edwards,K.J., Orcutt, B.N. 2015. Microbial Communities on Seafloor Basalts at Dorado Outcrop Reflect Level of Alteration and Highlight Global Lithic Clades. Frontiers in Microbiology 6:1470. C-DEBI Contribution 286. 

Orcutt, B. N. et al. 2013. Oxygen consumption rates in subseafloor basaltic crust derived from a reaction transport model. Nat. Commun. 4:2539. C-DEBI Contribution 166.

Note: This project was funded by a C-DEBI Research Grant.

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