These funds support the participation of students and early career scientists at a major international workshop held by in Oman in January 2011 by the International Ocean Drilling Program, the International Continental Scientific Drilling Program, the European Science Foundation, and others on the geological aspects of carbon sequestration in mafic and ultramafic rocks. The workshop site is close to one of the best 3-D exposures of ocean crust on Earth and will allow field trips and first hand observations of how carbon occurs and is distributed in mafic and ultramafic rocks by various processes involved in carbon capture and storage. Given the importance of finding ways to reduce the amount of CO2 in the atmosphere, this workshop is both important and timely; and it is being convened by the leading experts in the field from nine countries. A main goal of the workshop is to discuss the potential for carbon sequestration in seafloor basement rocks and their exposed remnants on the continents. Utilization of funds will be determined by competition using a set of established priority criteria. The opportunity to attend will be advertised widely to the academic and geological communities. Broader impacts of the work include investigating possible new means and reservoirs for CO2 storage and reducing levels of atmospheric CO2, building potential collaborations between academics and industrial and international partners, and promoting interaction between US and Middle Eastern scientists. The work will also support the attendance of students, postdocs, and early career faculty members helping to build workforce in the important area of carbon sequestration.
A workshop report is available online on several sites including www.ldeo.columbia.edu/gpg/publications The URL listed here is to Kelemen's group web site at LDEO, which we are confident is "somewhat" permanent. Two files among the 2011 publications downloadable from that site contain a short and long version of our workshop report. The short version contains only proceedings and results. The long version contains these, plus abstracts for all oral and poster presentations, PDF versions of graphics for each oral presentation, and the guide for the post-meeting field trip. NSF support is clearly acknowledged in these Reports. The workshop partially supported by this grant combined scientific communities associated with the Integrated Ocean Drilling Program (IODP) and the International Continental Scientific Drilling Program (ICDP) with colleagues from the geothermal, chemical, and mining industries to raise the profile of research on geological carbon capture and storage, with particular focus on the potential for storage in ultramafic and mafic rocks. In addition to ICDP and IODP, the workshop was sponsored by Sultan Qaboos University, the (US) National Science Foundation, the European Science Foundation, UK-IODP, InterRidge and the (US) Consortium for Ocean Leadership. Keynote lectures were on geological storage of CO2 in "mafic" and "ultramafic" rock formations (rocks rich in Magnesium and Iron, and poor in Silicon and Aluminum, which are best for this use), experimentally determined rates of CO2 reaction with rocks, processes in which volume expansion due to formation of carbonate minerals lead to fracture, maintaining or enhancing permeability and reactive surface area, experience with monitoring permeability and CO2 storage at sea and on land, use of ultramafic mine tailings for mineral carbonation for CO2 storage, ongoing projects involving CO2 injection into mafic rocks, and methods for engineered hydraulic fracture – enhancing permeability – in the geothermal power and mining industries. Mineral carbonation via injection of CO2-rich fluid into rocks at depth has the advantages that it can store almost unlimited amounts of carbon, and that rapid mineral carbonation occurs at the optimal conditions of high CO2 pressure and high temperature, but the disadvantages that the initial permeability of the rock formations may be low, and that the mineral carbonation process will have unknown effects on the reaction rate over time. Mineral carbonation can affect the reaction rate via negative feedbacks – filling of pore space and armoring of reactive surface area – or positive feedbacks – reaction driven cracking increasing permeability and surface area. Experimental data show that ultramafic rocks – for example peridotites in the Oman Mountains – form solid carbonate minerals 100’s to 1000’s of times faster than mafic rocks such as basaltic lavas in places such as Iceland and the US. However, the experimental data are incomplete, with few experiments run at exactly the same conditions of temperature, pressure and fluid composition for both mafic and ultramafic rock reactants. Use of air or seawater as a CO2 transport fluid avoids the cost of industrial CO2 capture and transport, but is chemically more difficult as the concentrations of CO2 in these fluids are low. Use of CO2-rich water or purified CO2 leads to more rapid mineral carbonation, but involves the potentially high costs of indutrial CO2 capture and transport from the generation site to the storage site. This grant provided travel and accommodation support to 11 young US scientists, including graduate students Caitlin Augustin (Rosensteil, U Miami), Claire Bendersky (LDEO, Columbia), Amelia Paukert (LDEO, Columbia), Pablo Garcia del Real (Stanford), Natalie Johnson (Stanford), Harrison Lisabeth (University of Maryland), Jagan Mahadevan (U Tulsa), and Jason Ornstein (NYU), postdocs Valentina Prigiobbe (Jackson, UT Austin) and Masako Tominaga (WHOI), and assistant professors Marc Hesse (Jackson, UT Austin) and Joshua West (USC). Many of the participants in the mineral carbonation workshop co-authored a proposal to the International Continental Scientific Drilling Program (ICDP) for an international workshop to be held on drilling in oceanic crust and upper mantle thrust onto the continental platform in Oman, based in part on discussions during the workshop. The ICDP workshop proposal was approved, so that a follow-on workshop will be held in Oman sometime in late 2012 or early 2013. One main focus of the proposed Oman Drilling Project will be study of the relationship between mineral hydration and carbonation, permeability, fracture formation, porosity, and reactive surface areas, in preparation for possible pilot experiments on engineered in situ mineral carbonation methods in Oman. Proposed drill sites include shoreline sites in carbonate cap rocks overlying mantle peridotite, which would allow nearshore, subseafloor experiments on mineral carbonation in peridotite. Another major focus will be study of geochemistry, subsurface microbial communities, and physical processes in all parts of the active peridotite alteration system in Oman, from the recharge zone to the reaction zone to the alkaline springs that are analogous to sub-sea hydrothermal vents. Interested scientists are urged to take part.
