Fluid Geochemistry
Disciplinary Groups: Fluid Geochemistry
Moderator: Bill Seyfried, Co-moderator: Bill Lavelle
PARTICIPANTS:
John "Chip" Breier, particle chemistry
Meg Tivey, vent deposits, mixing processes
Tom McCollom, modeling of mixing
Andrew Madison, (advisor: George Luther) electrochemistry EPR Lau
Peter Canovas, (advisor: Everett Shock) modeling of mixing
Ariel Bennett, (advisor: Mitch Schulte) model fluid mixing, abiotic origins
Mikella Rough, (advisor: Bill Seyfried) fluid-rock experiments
John Jamieson, (advisor: Mark Hannington) vent deposits, mineralogy, ore deposit
Nick Pester, (advisor: Bill Seyfried) phase separation
Florencia Prado, (advisor: Karen Von Damm and Julie) data collection and analyses of fluid chemistry, trace metals
Joe Resing, hydrothermal plumes
Ed Baker, finding vents and quantify heat flux
Peter Rona, mineralization and flow/flux of diffused and focused flow, acoustic methods
Bill Lavelle, modeling circulation of ocean circulation around ridges
GOAL OF DISCUSSION:
*Identify what still needs to be done? Particularly between ISS locations?
*Are there fundamental limitations to determine how to generalize between locations
Ex: silica - are vents quartz saturated; using silica as geothermometer - do we know whether it works? (in reference to reaction zone circulation of water)
Ex: do we know the role of compositional variability sufficiently to generalize; temp-pressure-SiO2 in reaction zone is critical
DATA AVAILABILITY:
• we do have comprehensive high temperature datasets, gas data at all 3 sites
• as a group we endorse that all data be made available to everyone ASAP
• raw vs. processed data - we would like to see both in VentDB (Mike Mottle and Kirsten Leinhert) - include the Mg, provide the endmember, but can get back to the raw data
• can we ask for proposal call to fund publication/data reports to get the pre-R2K field data and harvesting data outside the ISS (data was originally collected opportunistically with no funding for processing/publishing)
DATA GAPS:
1. trace metals (REE, Cu, Zn, Pb, Ba) are a HUGE data gap
2. no full fluid composition of diffuse flow
3. no systematic sampling of intermediate temperatures (15-30 degree fluid sampled heavily for biology) - no one samples these samples because their interests do not lie in that region
4. what is the metal deposition efficiency?
some vents dump most metals, some lose them to water column that can then be used
5. fluxes from diffuse sources vs. concentrated (mass, heat, chemistry fluxes)
BIG QUESTIONS THAT CAN BE ANSWERED WITH COLLABORATIONS:
1. connecting tidal currents and temps inside chimneys (physical and chemical)
2. differences in fauna occupying chimney - chemistry of chimney, temp, porosity controls?
organisms (early colonizers) affect chimney formation
ripe for proposal joint between biologists, vent deposits, circulation/physical oceanography
3. what is the role of chemistry in influencing biogeography?
4. connections between experimental data to help test hypotheses with existing field datasets
5. acoustic observations of diffuse flow might be relevant to biology, chemistry, and time variations - using time series monitoring should be made concurrent with bio/chem data collection
6. where is all the brine going?
7. what are the fluxes?
what is the aerial extent of diffuse flow?
measure integrated vent field heat flux, then measure heat flux of smokers in that field, then get diffuse flux by difference
also use tracers that get you fluid flux
ABE is good method to achieve this
8. what is the subsurface crustal structure?
9. modeling-observational collaborations need to be supported
10. sorting biogeography from physical, chemical environments/variability
11. many initiatives will require collaboration with engineers and other disciplines
NEW TECHNIQUES THAT COULD LEAD TO COLLABORATION:
• 226Ra/Ba ratio to date sulfides (must have Barite, 1 wt% barium in sample) - 500-20000 years - venting history - samples on JfD, assume starting ratio does not change over time = mass accumulation rates for vent field
• experimental technique for phase separation
PRE-MEETING QUESTIONS:
Discussion topics (list ideas and suggestions here):
Are cross-ISS comparisons useful in identifying fundamental controls on the temporal evolution of vent fluid geochemistry at any of the specific ISS sites?
Are there sufficient data (chemical, physical and biological) available to account for process controlling reactions that can affect fluid geochemistry for the IS-sites?
Are there disciplinary collaborations that could help to integrate existing datasets?Is there a role for non-ISS datasets to help with integration and synthesis of ISS datasets?
Controls on the Linkages between fluid geochemistry and vent mineralization/biological processes
THOUGHTS POSTED DURING DISCUSSION:
Data Gap?
Bill
Does compositional variability controls this?
Nick:
Can Si constrain deep reaction?
Jen:
Below is a diagram that I drew during the conversation that represents what I saw as the main contributions to a broader audience and the connections we can make with the data we have with possible connection points for collaboration. Also attached is a file hopefully in a format that you can download to make your own changes/additions.
