Themes and Sessions

07a: Vertical Evolution of Hydrothermal Ore-Forming Sytems: From the Mantle to the Surface
Convenors: James A Saunders, David John
Keynotes: Graham Begg (Scottish Crop Research Institute) , Jacob Lowenstern (USGS)
Orals: Wed AM
Posters: Tue PM
Mineral explorationists and "academic" economic geologists during the last decade have increasingly recognized that hydrothermal ore-forming processes may have their roots in magma formation in the upper mantle. Some of the metallic mineral deposits are associated with shallow volcanic processes and extend to the surface. Although this concept currently is being used in mineral exploration and is supported by limited new Pb- and Re-Os-isotope data, clearly more research efforts need to be focused in this area.
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07b: Fluid and Melt Inclusions: The State of the Science and Future Prospects
Convenors: Robert Bodnar, Volker Luders
Keynote: Zhenzao Duan (Institute of Geology and Geophysics, CAS)
Orals: Tue AM
Posters: Tue PM
Fluid and melt inclusions provide our best source of information concerning the composition, temperature and pressure of fluids associated with a wide range of geologic processes in the crust and mantle. This session will consider recent advances in the analysis and interpretation of fluid and melt inclusions from a wide range of geologic environments, including sedimentary basins, hydrothermal ore deposits, volcanic systems, subduction environments, the upper mantle and diamond source regions, and ultra-high pressure metamorphic environments.
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07c: Processes at the Source – Nano to Tectonic Scale Forces Driving Ore Formation
Convenors: Iain Pitcairn, Holly Stein
Keynote: Ross Large (School of Earth Sciences, University of Tasmania)
Orals: Mon PM
Posters: Mon PM
Sedimentary, metamorphic and magmatic rocks are all capable of acting as a source of fluids and metals for ore formation. Identification of source areas is a crucial ingredient for understanding ore formation and identifying prospective terranes. Release of metals and volatiles from their source, and sustained transport and consolidation of critical ore-forming components, are fundamental processes to defining ore potential. This session focuses on the identification and significance of source, the processes that control mobility of metals and fluids within source regions, and their collective significance for ore formation. We invite contributions from researchers working on the full spectrum of ore classes. Contributions focused on nano to tectonic scale processes are encouraged. Specific contributions may include insight from (1) stable and radiogenic isotopes as tracers through time, (2) hydrocarbons, (3) connections between source areas and end products, (4) characteristics of source areas for exploration, and (5) the role of source area in the creation of large metallogenic provinces.
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07d: Mineral Nanoparticles and Nanominerals in Ore Systems and their Environmental Geochemistry
Convenors: Martin Reich, Satoshi Utsunomiya, Robert Hough
Keynote: Robert Hough
Orals: Mon PM
Posters: Mon PM
Nanoscale phases are receiving significant attention due to their unique role as agents of elemental transport and enrichment in ore systems and supergene, near-surface settings. This session aims to provide an overview of nanomineralogy of ore deposits and mining environments, and to present recent advances in understanding metal transport, deposition and enrichment under hypogene and supergene conditions, with or without biological mediation. Contributions are invited on all aspects of nanomineralogy applied to mineral deposits, including - but not limited to - base and precious metal "ore" nanoparticles, metal speciation in solution and its relation with colloidal transport, and magmatic/hydrothermal, supergene, and biogenic processes at the nanoscale. The session will cover research using all types of high-resolution techniques and computational methods, including HRTEM, HRSEM, SIMS, synchrotron XAS, XPS, AFM/STM, and atomistic modeling applications to ore deposits and their environmental residues.
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07e: Accessory Phase Elemental and Isotopic Geochemistry: Micro-Analytical Tools and Petrologic Applications
Convenors: Rita Economos, John Ayers, John Dilles
Keynote: Bruce Watson (Rensselaer Polytechnic Institute)
Orals: Mon AM
Posters: Mon PM
The limitations of whole rock trace element analyses in accessing the history of complex processes undergone by a single sample are leading to a broad-scale interest in single mineral analyses. In-situ micro-analysis of zircon, titanite, apatite, and other accessory phases present new opportunities for constraining magmatic processes and sampling lower crustal sources. Further, some accessory phases provide constraints on time, temperature, elemental composition, and isotopic composition from the same grain, yielding robust and powerful new datasets. These analyses have wide potential applications, including constraints on magmatic oxidation state and fluid-melt evolution in metallogenic systems, the dynamics of the lower crust in batholith formation and collisional orogenesis, among many others. This session brings together practitioners of micro-analytical technique development, experimental geochemists, and those who seek to apply these techniques to an increasing range of geologic problems.
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03i: Trace Element Partitioning
Convenors: Wim van Westrenen, James Van Orman, John Ayers
Keynote: Dan Frost (Bayreuth)
Orals: Thu AM
Posters: Thu PM
Trace element partitioning data form a cornerstone of quantitative models of a wide range of planetary differentiation processes including crust and core formation, magma generation at ridges and hot spots, and element mobilization in subduction zone settings. Exciting recent developments in the partitioning arena include improving ability to measure noble gas partitioning and mineral-fluid partitioning, and to assess partitioning processes using computer simulations. We are inviting contributions focusing on trace element partitioning in mineral-water, mineral-melt, metal-silicate and metal-metal systems.
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04l: Earth Materials: Thermodynamic and Energetic Properties
Convenors: Charles A. Geiger, Artur Benisek
Keynotes: Guy Hovis (Lafayette College, Easton) , Viktor Vinograd (Goethe Universität, Frankfurt)
Orals: Tue PM
Posters: Tue PM
Study of the thermodynamic behavior of various Earth materials plays a central role in the fields of geochemistry, mineralogy, petrology and geophysics. This session will be devoted to studies, experimental, theoretical and computational, in the area of thermodynamic and energetic behavior of all types of Earth materials. This includes minerals, glasses, fluids, nanophases and surfaces. Several areas will receive special emphasis such as: low-temperature heat capacity determinations, new theoretical and computational developments, thermodynamic behavior of high-pressure phases, mineral-fluid interactions and nanophases.
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04o: Geochemistry and Trace Elements in gem Materials
Convenors: Emmanuel Fritsch, Benjamin Rondeau
Orals: Mon PM
Posters: Mon PM
Trace elements in gems have proven extremely useful to solve a range of specific gemological issues. First, the classical challenges of the separation of natural from synthetic or treated stones have reached new territories by the introduction of geochemical methods and instrumentation (ICPMS-LA, LIBS, etc.). Of burning actuality also is the identification of gems geographical source, including historical trade routes, for which geochemistry has lifted numerous ambiguities. By contributing to the understanding of gems genesis, geochemical studies also produce leads for prospection. This session aims at grouping presentations highlighting the new roles of geochemistry in gemology (including archaeogemology), no matter what approach is taken, for example trace elements, isotopes, or geochemistry of gem deposits.
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05c: Dynamics and Energetics of Seafloor Hydrothermal Systems
Convenors: Andrew McCaig, Mathilde Cannat, Fabrice Fontaine
Keynote: William Wilcock (University of Washington)
Orals: Mon AM
Posters: Mon PM
Seafloor hydrothermal circulation is a vital part of the Earth System, conditioning both the lithosphere entering subduction zones and the chemistry of the ocean. Recent work has highlighted the diversity of hydrothermal systems both in the near-ridge high temperature environment and off-axis. Order of magnitude variations exist in the scale (heat output) and longevity of circulation, related to factors such as spreading rate, magma chamber depth and geometry, and tectonics. Modelling such systems requires an understanding of the complex interplay between heat input, permeability structure of the lithosphere and the thermodynamic properties of seawater as it changes in P,T and chemistry during hydrothermal flow. We invite contributions on all aspects of the dynamics and energetics of seafloor hydrothermal circulation, including modelling and the testing of models, links between seismicity and hydrothermal circulation, controls on permeability including deformation and metamorphic reactions, and the longevity and episodicity of flow.
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08c: Geochemical Processes in Continental Collision Zones
Convenors: Yong-Fei Zheng, Bill C. McClelland, Shuguang Song, Simon Cuthbert, Lingsen Zeng
Keynotes: Gray E. Bebout (Lehigh University) , Yaoling Niu (Durham University)
Orals: Thu AM, Thu PM, Fri AM
Posters: Thu PM
Geochemical processes in continental collision zones are associated with different depths of crustal subduction/exhumation and associated mineralogical changes. They are a key to understanding a wide spectrum of phenomena, involving HP/UHP metamorphism and syn-/post-collisional magmatism. In particular, metamorphic dehydration and partial melting of subducting and exhuming HP/UHP metamorphic rocks are vital to syn- and post-collision magmatism. This session deals with various aspects concerning continental collision zones and encourages the linkage of different methods to solve macroscale to microscale questions. Potential topics include the tectonic affinity of subducted continents, transition from oceanic subduction to continental collision, crust-mantle interaction during continental subduction/exhumation, the time and duration of HP/UHP metamorphism, fluid effects on phase equilibria and P-T estimates, accessory minerals and trace elements, the generation and action of aqueous fluid and hydrous melt, element and isotopic mobility, the scale and magnitude of crustal melting, lithospheric extension and orogenic collapse, and syn- and post-collisional magmatism.
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08e: The Eclogite – Arc Magma Connection: Linking Metamorphic and Igneous Processes at Subduction Zones
Convenors: Maureen Feineman, Sarah Penniston-Dorland, Alicia Cruz-Uribe, Jeffrey Ryan
Keynotes: Richard Arculus (ANU) , Craig Manning (UCLA)
Orals: Fri PM
Posters: Thu PM
Arc lavas contain abundant evidence for the involvement of aqueous fluids in their production, and subduction-related metamorphic rocks from some localities show petrological and geochemical evidence for large fluxes of aqueous fluid. This session aims to link studies of fluid production by metamorphic reactions in and around the subducting slab to studies of fluid-mediated arc magma production in the mantle wedge. These two regimes are linked by fluid transport processes across the slab-mantle interface, which may themselves affect the composition of the fluid. We encourage contributions pertaining to fluid production and transport at metamorphic conditions, fluid transport in the mantle wedge, and slab-derived fluid contributions (volatiles, trace elements, isotope ratios) to arc magmas. We invite disciplinary and interdisciplinary submissions that use analytical, field, modeling, and experimental techniques to elucidate the processes of fluid production, transport, and evolution that ultimately lead to the generation of arc magmas.
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08g: Simulation of Metamorphic Processes – Theory, Experiments, and Numerical Models
Convenors: Peter Nabelek, Jay Ague
Keynotes: Sumit Chakraborty (Ruhr-Universität, Bochum) , John Ferry (Johns Hopkins University)
Orals: Thu AM
Posters: Thu PM
This session seeks to highlight ongoing research on modeling of metamorphic processes and their time scales, including nucleation and growth of minerals, stability of mineral assemblages, fluid flow, heat transfer, and mass transport through diffusion and advection. Contributions are sought from those workers who develop models based on theory, experiments and numerical calculations that support field and petrologic observations in both regional settings and contact aureoles. Presentations that highlight application of metamorphic processes theory to tectonics and the physical and chemical structure of the lithosphere are encouraged.
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09d: Fracturing and Cementation; Geochemical and Mechanical Feedback Processes
Convenors: Stephen E. Laubach, Richard Worden
Keynote: Leonel Gomez (ExxonMobil)
Posters: Mon PM
Understanding fractures and faults is important in many areas of geosciences. Recent evidence from unconventional natural gas reservoirs shows that fracturing and cementation are commonly linked processes in these rocks, and that geochemical and mechanical feedback processes may govern key elements of fracture systems capacity to transmit fluids as well as other attributes. Previous and ongoing work in fault systems demonstrates that understanding linked geochemical and mechanical processes are essential for deciphering key aspects of how fault systems evolve. Structural diagenesis is a new perspective for understanding how fracturing, fault growth, compaction, and other mechanical processes interact with chemical processes to govern the attributes of structures and physical properties of sedimentary rocks at high crustal levels in the Earth. Although clearly a characteristic part of the postdepositional changes that affect rock, fractures and faults are commonly neglected in conventional diagenetic studies, which thus miss an essential aspect of the transformation of sediment into rock. Likewise, structural studies, at least those concerned with the low-temperature realm of sedimentary basins, tend to focus on geometry, kinematics, and mechanics. Thermal controls and chemical processes are commonly ascribed limited importance, if considered at all. Yet much can be learned about chemical diagenesis by reference to structure, and vice versa, and chemical and mechanical processes may be coupled in many ways. There are undoubtedly many important feedbacks between them. Cross-disciplinary research is beginning to address some of these issues, but systematic training in principles of both structure and diagenesis is the key to unlocking scientific knowledge about a part of the Earth's interior that is of great intrinsic and practical interest. These challenges call for a merger of disciplines and a new training paradigm in sedimentary geochemistry and structural geology.
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18h: Structure and Properties of Silicate Melts, Glasses and Fluids
Convenors: Xianyu XUE, Mark Ghiorso, Grant Henderson
Keynotes: Bjorn Mysen (Bjorn Mysen) , Jonathan F. Stebbins (Stanford Univ.)
Orals: Tue AM
Posters: Tue PM
This session will bring together frontier studies on the structure and properties of silicate (and related) melts, glasses and fluids at both ambient and high pressures. Active interactions between experimental studies (spectroscopic and diffraction measurements, physical and thermodynamic property measurements, etc) and modeling (molecular dynamics and first principles calculations, thermodynamic modeling, etc.) are in particular anticipated. The subject is of key importance for understanding both natural magmatic processes and technological materials (e.g. nuclear waste glasses, slags), and thus contributions from multiple disciplines are encouraged.
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20n: Laser Ablation ICP-MS in Ore Deposits Studies
Convenors: Sarah-Jane Barnes, Alan Koenig, Marcel Guillong
Keynotes: Marc Norman (The Australian National University) , Thomas Pettke (University of Bern)
Orals: Mon AM
Posters: Mon PM
Laser ablation ICP-MS (LA-ICP-MS) has been successfully applied to the determination of lithophile elements in silicates minerals in number of petrogenetic problems. Recently LA-ICP-MS has been applied to ore deposits studies with a wider range of trace elements being determined in minerals and fluid inclusions. The application of LA-ICP-MS to ore deposits studies produces some unique analytical problems; the unusual combination of elements in ore deposits may produce unusual interferences; reference materials for many chalcophile and siderophile elements are not widely available or validated, the matrix materials common in ore deposits; sulfides, oxides and fluids, ablate very differently to glasses that are commonly used as reference materials. This session will address: a) analytical challenges related to LA-ICP-MS for ore deposit studies, including reference materials and trace element or isotopic mapping; b) application of LA-ICP-MS to ore deposits modeling and exploration.
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