Award Abstract # 0711333
Accomplishment Based Renewal: Experimental Studies of the PTX Properties of Immiscible Fluids at Crustal PT Conditions

NSF Org: EAR
Division Of Earth Sciences
Recipient: VIRGINIA POLYTECHNIC INSTITUTE & STATE UNIVERSITY
Initial Amendment Date: May 29, 2007
Latest Amendment Date: April 12, 2010
Award Number: 0711333
Award Instrument: Continuing Grant
Program Manager: William P. Leeman
EAR
 Division Of Earth Sciences
GEO
 Directorate for Geosciences
Start Date: July 1, 2007
End Date: December 31, 2010 (Estimated)
Total Intended Award Amount: $0.00
Total Awarded Amount to Date: $378,110.00
Funds Obligated to Date: FY 2007 = $122,692.00
FY 2008 = $115,332.00

FY 2009 = $121,365.00

FY 2010 = $18,721.00
History of Investigator:
  • Robert Bodnar (Principal Investigator)
    rjb@vt.edu
Recipient Sponsored Research Office: Virginia Polytechnic Institute and State University
300 TURNER ST NW
BLACKSBURG
VA  US  24060-3359
(540)231-5281
Sponsor Congressional District: 09
Primary Place of Performance: Virginia Polytechnic Institute and State University
300 TURNER ST NW
BLACKSBURG
VA  US  24060-3359
Primary Place of Performance
Congressional District:
09
Unique Entity Identifier (UEI): QDE5UHE5XD16
Parent UEI: X6KEFGLHSJX7
NSF Program(s): Petrology and Geochemistry,
Instrumentation & Facilities
Primary Program Source: app-0107 
01000809DB NSF RESEARCH & RELATED ACTIVIT

01000910DB NSF RESEARCH & RELATED ACTIVIT

01001011DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s): 0000, OTHR
Program Element Code(s): 157300, 158000
Award Agency Code: 4900
Fund Agency Code: 4900
Assistance Listing Number(s): 47.050

ABSTRACT

Intellectual merit: Immiscibility (boiling) in fluids approximated by the H2O-CO2-NaCl-KCl- CaCl2 system is common in many crustal environments, including epithermal precious metals deposits, porphyry copper-gold-molybdenum deposits, metamorphic lode gold deposits and other crustal igneous and metamorphic environments. Fluid immiscibility is an effective mechanism for partitioning and concentrating certain elements into one or the other of the two coexisting phases and thus plays an important role in crustal geochemical processes. Fluid inclusions provide the best evidence for the occurrence of fluid immiscibility in these environments, but our ability to interpret microthermometric and microanalytical data from natural inclusions is limited by the lack of experimental PTX data on compositions of coexisting fluids at crustal pressure-temperature (P-T) conditions. Experiments will be conducted using the synthetic fluid inclusion technique to determine compositions of coexisting fluids in the H2O-CO2-NaCl, H2O-NaCl-KCl and H2O-NaCl-CaCl2 ternary subsystems. The P-T limits of immiscibility will be defined based on observations of synthetic fluid inclusions trapped at known conditions. Fluid inclusions trapped in the one-phase fluid field all show identical room temperature phase relations and microthermometric behavior. Those trapped in the two-phase field show a bimodal distribution of phase behavior, indicative of the liquid and vapor phases that were present at elevated temperature and pressure. Compositions of the coexisting liquid and vapor phases will be determined from microthermometric analyses, interpreted using previously determined data for the appropriate fluid system, and supplemented by Raman spectroscopy to identify daughter minerals and to determine the H2O/CO2 ratio of CO2-bearing inclusions. The proposed research represents a continuation of ongoing experimental efforts designed to provide fundamental PVTX data on geologically-relevant fluids so that we may better understand the critical role that fluids play in the geochemical and rheological evolution of the crust and upper mantle.

Broader impact: Funding provided by this grant will provide training for graduate students and help prepare them for successful careers in the earth sciences. This project will also support one or more undergraduate students each year to provide a meaningful research experience. The broader impacts also include lectures and workshops on Fluids in the Earth that the PI offers to students and professionals worldwide, as well as teaching introductory earth sciences courses to non-science majors at Virginia Tech. These activities reflect the broader impacts of the PI's research and the important role that quality undergraduate education plays in developing a scientifically literate society.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

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Becker SP, Fall A & Bodnar RJ "Synthetic Fluid Inclusions XIX. PVTX properties of high salinity H2O-NaCl solutions (>30 wt.% NaCl), with application to inclusions that homogenize along the halite liquidus." Economic Geology , v.103 , 2008 , p.539
Becker SP, Fall A & Bodnar RJ "Synthetic Fluid Inclusions XIX. PVTX properties of high salinity H2O-NaCl solutions (>30 wt.% NaCl), with application to inclusions that homogenize along the halite liquidus." Economic Geology , v.103 , 2008 , p.539
Berkesi, M.; Hidas, K.; Guzmics, T.; Dubessy, J.; Bodnar, R.J.; Szabo, Cs.; Vajna, B.; Tsunogae, T. "Detection of small amounts of H2O in CO2-rich fluid inclusions using Raman spectroscopy" Journal of Raman Spectroscopy , v.40 , 2009 , p.1461 http://10.1002/jrs.2440
Bodnar, RJ "GEOLOGY Heavy Metals or Punk Rocks?" SCIENCE , v.323 , 2009 , p.724 View record at Web of Science 10.1126/science.116639
Fall, A; Rimstidt, JD; Bodnar, RJ "The effect of fluid inclusion size on determination of homogenization temperature and density of liquid-rich aqueous inclusions" AMERICAN MINERALOGIST , v.94 , 2009 , p.1569 View record at Web of Science 10.2138/am.2009.318
Fall, A.;Tattitch, B.;Bodnar, R. J.; "Combined microthermometric and Raman spectroscopic technique to determine the salinity of H2O-CO2-NaCl fluid inclusions based on clathrate melting" Geochemica et Cosmochemica Acta , v.75 , 2011 , p.951-964
Hidas, K; Guzmics, T; Szabo, C; Kovacs, I; Bodnar, RJ; Zajacz, Z; Nedli, Z; Vaccari, L; Perucchi, A "Coexisting silicate melt inclusions and H2O-bearing, CO2-rich fluid inclusions in mantle peridotite xenoliths from the Carpathian-Pannonian region (central Hungary)" CHEMICAL GEOLOGY , v.274 , 2010 , p.1 View record at Web of Science 10.1016/j.chemgeo.2010.03.00
M. Steele-MacInnis, R. J. Bodnar and J. Naden "Numerical model to determine the composition of H2O-NaCl-CaCl2 fluid inclusions based on microthermometric and microanalytical data" Geochimica et Cosmochimica Acta , v.75 , 2011 , p.21 doi:10.1016/j.gca.2010.10.002

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

Fluids play an important role in many geologic processes, including the formation of petroleum and mineral deposits, the triggering of earthquakes and volcanic eruptions, and transporting heat through the earth's crust. In order to predict the extent to which these fluid-assisted processes influence the evolution of the earth, detailed quantitative information concerning the properties of natural fluids over the complete range of temperature, pressure and fluid composition conditions encountered in crustal environments is required. One of the best methods available to determine the role of fluids in natural environments is through the study of fluid inclusions, which are small droplets of fluid or melt that are trapped in minerals when they form at great depths in the earth (See Figure). Complete and accurate interpretation of data obtained from fluid and melt inclusions requires information on the properties of these fluids at high temperatures and pressures.

 

Natural brines rich in sodium and calcium chloride salts are common in may sedimentary basins that occur on the continents. These basins host many of the petroleum and natural gas deposits being produced for energy, as well as mineral deposits for lead, zinc, copper and other metals. In this study we have determined the properties of H2O-NaCl-CaCl2 fluids and have developed a numerical model that can be used to interpret results obtained from fluid inclusions formed in these environments. This, in turn, allows workers to develop more accurate models to explore for resources in sedimentary basins.

 

Sedimentary basins are also considered to be one of the best sites for the long-term storage of carbon dioxide produced by burning of fossil fuels. However, little is known about the long-term behavior of the subsurface reservoirs following CO2 injection. In this project we developed a technique to accurately determine the salinity of fluid inclusions containing brines and carbon dioxide. This method allows us to better characterize the compositions of fluids in sedimentary environments containing high salinity brines and carbon dioxide.

 

One of the most important factors controlling the nature of volcanic eruptions is the composition and amount of gases contained in the magma body beneath a volcano. One of the best techniques to determine the gas (volatile) content of magmas is to study melt inclusions that are trapped in the magma chamber before the eruption. In this project we developed a quantitative model that describes how the volatile composition of melt inclusions evolves after the melt is trapped at depth and during the subsequent eruption. These data are critical to develop a better understanding of the mechanisms and processes associated with explosive volcanic eruptions, such as the 1980 Mt. Saint Helens eruption and the one that destroyed Pompeii in 79 AD.  


Last Modified: 06/30/2011
Modified by: Robert J Bodnar