Black carbon, produced by incomplete combustion of fossil fuels and vegetation fires, is relatively resistant to degradation and occurs ubiquitously in natural environments, including soils, sediments, seawater and the atmosphere. In recent years, geochemical and biological studies of different forms of black carbon (such as plant chars, charcoals, and soots) received increasing attention due to potential importances in a wide range of biogeochemical processes. For example, black carbon may represent a significant sink in the global carbon cycle, affect earth’s radiative heat balance, be a useful tracer for earth¹s fire history, be a significant fraction of carbon buried in soils and sediments, and be an important carrier of organic pollutants.

 Black carbon is presently being studied in a variety of widely separated scientific fields, with the result that essentially no generally accepted analytical protocols, terminologies and conceptual approaches exist. The aim of the symposium is to bring together a broad collegium of scientists ranging from geochemists to biologists and paleoenvironmentalists, to discuss the biogeochemical roles of black carbon in natural environments. In addition to stimulating interdisciplinary approaches, an additional goal of this symposium will be to encourage establishment of a collection of black carbon reference materials and to facilitate their comparative analysis by a range of commonly used techniques.

 This emerging field of biogeochemical research will be addressed in two days of oral and poster presentations, including a special session dedicated to discussing potential comparison exercises. This symposium should attract a large number of participants from a broad and diverse background in carbon biogeochemistry, certainly including soil, sediment, and marine geochemists and biologists.

Michael WI Schmidt, Max-Planck-Institut fur Biogeochemie, Germany

Tel. +49 3641 6437-23 E-mail: michael.schmidt@bgc-jena.mpg.de

Orjan Gustafsson, Stockholm University, Environmental Research Institute (ITM), Sweden

Tel. +46 8 6747317 email: orjan.gustafsson@itm.su.se

John Hedges, University of Washington, School of Oceanography, USA

Tel. +1 206 543 0744 E-mail: jihedges@u.washington.edu

Session chairs: R.J. Parkes, T. Ferdelman and G. King

Microbes dominate the biogeochemical cycling of organic matter, but relatively little is known about relationships between the activity of the relevant heterotrophs and the dynamics of organic matter cycling. The production of low molecular weight compounds (e.g., methane, short chain carboxylic acids, and related compounds) from macro-molecular organic matter is a poorly understood process regulated by equally poorly understood microbial consortia. While phylogenetic analyses have revealed much about the diversity and the evolution of certain functional groups (e.g., methane producers, sulfate reducers, methanotrophs),phylogenetic novelty has often been described without clear connections to geochemical processes. Conversely, geochemists are often unaware of the new techniques available for exploring the diversity and functioning of the microbial communities that underlie the processes they are studying.

Thus, this symposium seeks to address several broad issues:

 how do microbial activities and diversity control the "reactivity" of organic matter?

 how can phylogenetic analyses improve predictive understanding of the fate and controls of organic matter cycling?

 how can the results of biogeochemical analyses inform interpretation of microbial community structure?

Possible themes may include temperature regulation effects on biogeochemical processes, microbial consortia and the cycling of methane and short-chain carboxylic acids, exo-enzymatic hydrolysis of organic matter, and phylogenetic analysis of natural microbial communities and their relationship to biogeochemical processes.

Dr. Timothy G. Ferdelman, Max Planck Institute for Marine Microbiology, Celsiusstr. 1, D-28359 Bremen, Germany

Tel: +49-(0)421-2028-ext office: -651; fax: -690; lab -620

Quantitative investigations focused on chemical equilibria and bioenergetics. Experimental, theoretical, and modeling studies of bacteria-water-rock interactions. Data that elucidate geochemical equilibria, kinetics, and bioenergetics of related reactions. Microbial metabolic strategies, heterogenous equilibria in biofilms, and biomineralogy.

 We hope to bring together a diverse group of researchers interested in the chemistry of the Precambrian environment, as well as those who use geochemical tools to unravel the complex geological and biological changes that occurred during this period of Earth history. Recent years have brought important advances in Precambrian studies, including some provocative ideas that suggest new research directions for geochemists. Simultaneously, the establishment of NASA's Astrobiology program has attracted new scientists to the field, and promises resources for research in Precambrian geochemistry. We believe this year's Goldschmidt conference is an outstanding opportunity for this growing community to discuss and debate the latest findings and proposals.

A. D. Anbar, Dept. of Earth and Environmental Sciences and Dept. of Chemistry, University of Rochester, Rochester, NY 14627

Phone: (716) 275-5923, Fax: (716) 244-5689, Email: anbar@earth.rochester.edu

Alan Jay Kaufman, Department of Geology University of Maryland College Park, MD USA

Direct line: (301) 405 0395, 20742-4211 Dept. office: (301) 405 4082, Dept. fax: (301) 314 9661 Email: kaufman@geol.umd.edu

 Recent discoveries made by Ocean Drilling in the Atlantic, Pacific and Indian Oceans have dramatically increased our knowledge of the composition and structure of the lower ocean crust. This in turn, has stimulated many scientists from the ocean earth sciences community to revisit layered intrusions to gain insight into how to interpret cores of coarse plutonic rock. While it is evident that there are many similarities, the environment of accretion is profoundly different, with continental intrusions forming in a relatively static environment while oceanic intrusions accrete in a remarkabley dynamic environment. How does the accretionary process in these two environments compare in rates of intrusion, time scales of crystallization, melt resupply, and melt transport processes. We are seeking papers on layered and oceanic intrusions both individually, and papers comparing them.

 Due to the recent increase in the number of analytical and experimental data, geophysical observations and numerical models, ideas about how melt is generated and extracted from the mantle are rapidly changing. This symposium will be a forum for discussing the constraints on the processes of melting and melt extraction from the mantle. We welcome abstracts presenting work on both the physical and chemical aspects of melt generation. This session should be a forum for discussing constraints from numerical modeling, seismological observations, and geochemical and petrological observations from lavas, melt inclusions or solid residues. Experimental work devoted to trace element partitioning, melt generation and migration and melt-solid interactions are also welcomed.

Kenneth W.W. Sims, Dept of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543

(508) 289-2634 office, (508) 457-2187 fax; Email: ksims@whoi.edu

Dr. Yaoling Niu , Department of Earth Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia

Telephone: 61-7-3365-2372 (O), 61-7-3372-4134 (H), FAX: 61-7-3365-1277

E-mail: Y.Niu@Mailbox.uq.edu.au or niu@earthsciences.uq.edu.au

14. Frontiers in Marine Chemistry

This symposium is a venue for papers dealing with all aspects of continent formation and evolution. Topics include, but are not limited to:

 the tectonic setting of crustal growth, specifically the relative contributions of convergent margin vs. intraplate magmatism

 the continental compositional paradox: why isn't the continental crust basaltic?

 is lower crustal and lithospheric mantle delamination a viable process?

 how important are slab melts and melt-mantle reaction in continent formation?

 how were thick lithospheric keels formed beneath Archean cratons and how robust are they to tectonic processing?

 has weathering had a profound influcence on bulk contiental crust composition?

 when did the present volume of continents form and how important is continent recycling throughout Earth history?

 are the continental crust and depleted mantle geochemically complementary to one antoher, or are additional silicate reservoirs required for elemental and isotopic mass balance?

 Isotopic data are increasingly applied as tracers of sources, transport, and chemical cycling of anthropogenic contaminants, such as Pb, Se, NO₃^-, chlorinated hydrocarbons, Pu and B, in water, sediments, and the atmosphere. This symposium will highlight results from important isotopic studies, including advances in analytical methods, investigations of reduction, biodegradation, and other chemical processes in the environment, and human epidemiology.

Thomas M. Johnson, Dept. of Geology, 245 Natural History Bldg. MC-102, 1301 W. Green St. Urbana, Il 61801

Phone: (217) 244-2002, FAX (217) 244-4996; tmjohnsn@uiuc.edu

Martin Schoonen: mschoonen@notes.cc.sunysb.edu

/meetings/gold99/gold99.htmlBack to Goldschmidt Conference Home page