S50: Where Bio meets Geo: The deep subsurface and other extreme environments

Conveners:	Kai-Uwe Hinrichs	(khinrichs@uni-bremen.de)
	Brian Horsfield	(horsf@gfz-potsdam.de)
Keynotes:	Tullis C. Onstott	(Princeton University, USA)
	Victoria J. Orphan	(Caltech, USA)
	Artur Spivak	(University of Rhode Island, USA)

This session seeks to emphasize the interplay of biological and geological processes in the deep subsurface and other extreme habitats. We hope to attract contributions from geochemists, geologists, and geomicrobiologists. Systems of interest include, but are not limited to, hydrothermal environments, cold to hot subsurface sediments, deep continental mines, water bodies with low to high pH or high salinity, hydrocarbon reservoirs, hydrate-bearing sediments and gas seeps, and deserts.

S51: Early evolution of life and bio/hydro/atmosphere

Conveners:	Jochen Brocks	(jochen.brocks@anu.edu.au)
	Emmanuelle Javaux	(EJ.Javaux@ulg.ac.be)
Keynote:	Roger Buick	(University of Washington, USA)

Through the Precambrian, life has left morphological, chemical and isotopic evidence of its evolution and has shaped oceanic and atmospheric processes. This session offers the opportunity to paleontologists and organic, inorganic and isotopic geochemists to address together topics related to the early evolution of life and its environment from the early Archean to the latest Proterozoic.

S52: Novel molecular & isotopic approaches in modern and paleo systems

Conveners:	Enno Schefuss	(schefuss@uni-bremen.de)
	Joseph P. Werne	(jwerne@d.umn.edu)
Keynote:	Stefan Schouten	(Texel, the Netherlands)

Critical aspects of the environment to reconstruct in order to understand climate change include temperature, hydrologic balance, and vegetation changes (both aquatic and terrestrial). State-of-the-art molecular and isotopic techniques supply a wealth of information related to all of these parameters, and application of these techniques to high-resolution sedimentary archives, such as lakes or ocean margin sediments, provides novel insights into the climatic coupling between oceanic and atmospheric circulation, hydrologic conditions, temperatures and the oceanic as well as terrestrial biosphere. In this session, we will bring together (paleo-) climatologists and organic geochemists to enhance awareness of recent analytical developments and guide the development of future biogeochemical methods based on current questions in (paleo-) climate research.

S53: Geochemical records of environmental and biotic change in the Phanerozic

Conveners:	Richard Pancost	(R.D.Pancost@bristol.ac.uk)
	Michael M. Joachimski	(joachimski@geol.uni-erlangen.de)
Keynote:	Kliti Grice	(Perth, Australia)
	Robert Berner	(Yale Uuniversity, USA)

Molecular biomarker and inorganic geochemical records have recently provided new insights into the evolution of the Earth's environment and biota. These include molecular records of microbial change and dramatic shifts in redox conditions associated with Phanerozoic mass extinctions as well as new isotopic records detailing the evolution of organic matter cycling through the Phanerozoic. The significance of these observations, and in particular the relationship between environmental and short- and long-term biological change, will become more clear as a broader range of sites is examined and novel approaches are developed. With this interdisciplinary approach in mind, we invite presenters employing a range of geochemical proxy techniques to contribute to this session. Papers highlighting new isotopic, trace element and molecular records are particularly encouraged, as well as papers interpreting such records using climate or geochemical modelling.

S54: Organic matter metal interaction

Conveners:	Jorge Spangenberg	(Jorge.Spangenberg@unil.ch)
Keynote:	John Parnell	(Aberdeen, Scotland)

Organic matter-metal interactions are key processes in various terrestrial and aquatic environments, including marine and fresh water systems, soils, sediments, nuclear and mine waste disposals, hydrothermal systems, and mineral deposits. Solid or liquid hydrocarbons may stabilize and concentrate the metals in natural fluids (geofluids) by sorption on organic colloids or forming organic carbon-metal ion binding. This session is open to all contributions from application of organic, inorganic and isotopic geochemistry to understanding the formation and evolution of the metal associations with natural organic matter in different terrestrial and extraterrestrial environments. Contributions describing the biogeochemical cycles of metals are also welcome.

S55: Stable Isotopes in environmental biogeochemistry

Conveners:	Bernhard Mayer	(bmayer@ucalgary.ca)
	Michael Boettcher	(michael.boettcher@io-warnemuende.de)
Keynote:	Ruth E. Blake	(Yale)

Stable isotope measurements play an essential role in advancing our knowledge in Biogeochemistry and Environmental Geochemistry. This session will highlight recent advances in the use of stable isotope techniques to gain a better understanding of sources and biogeochemical processes in marine and terrestrial ecosystems, including the role of microorganisms in cycling of elements. Contributions describing novel isotopic approaches in Applied Geochemistry are also welcome.

S56: Geochemical impact of anthropogenic activities on the riverine and coastal environment

Conveners:	Jan Schwarzbauer	(schwarzbauer@lek.rwth-aachen.de)
	Mark Fitzsimons	(m.fitzsimons@plymouth.ac.uk)

Although clean fresh water supply is essential for human well-being since decades anthropogenic activities are harming the aquatic environment. Rivers have been exploited as 'solvents' and carriers for liquid and solid human waste. Due to the high dynamics of riverine systems this has resulted in partially high contamination levels in and along rivers and corresponding coastal areas. However, the occurrence, fate and distribution for numerous anthropogenic contaminants and xenobiotics are still poorly understood. This session is open for all compound-related investigations leading to a better understanding of (i) environmental behaviour and impact of man-made chemicals and (ii) changes of natural conditions induced by anthropogenic activities. Presentations on new strategies or methods for characterizing and assessing the anthropogenic impact on riverine and coastal environment are welcome.

S57: Applications of hydrogen isotopes in organic geochemistry

Conveners:	Kliti Grice	(K.Grice@curtin.edu.au)
	Gerd Gleixner	(ggleix@bgc-jena.mpg.de)
Keynote:	Yongchun Tang	(UCLA, USA)

Topics for papers include, but are not limited to the application of stable isotope ratios of hydrogen preserved in sediments for identifying changes in the environment over short and long timescales or global isotopic excursions in the rock record (e.g. Permian/Triassic), assessing changes in water cycle, stable hydrogen isotope studies of extant organisms (algae, bacteria, land plants), applications in petroleum geochemistry (hydrogen exchange reactions, kinetics, source-rock evaluation), environmental forensics (source and fate of contaminants in soil, groundwater and atmosphere).

S58: Atmospheric Organic Pollutants: The role of and interplay with geochemistry

Conveners:	Kevin C. Jones	(k.c.jones@lancaster.ac.uk)
	Rainer Lohmann	(lohmann@gso.uri.edu)
Keynote:	Terry Bidleman	(Toronto)

Organic pollutants can enter the atmosphere in a variety of forms (e.g. from combustion, by volatilisation, as wind-entrained dusts). Once in the atmosphere, their fate (reactivity, transport distances, deposition processes, gas-particle partitioning) is intimately affected/controlled by their interaction with natural and anthropogenically derived aerosols and particulate matter. This session will explore the role of and interplay between airborne organic pollutants, and organic/inorganic aerosol phases, and the impact that geochemistry can have of the global cycling and impact of airborne organic pollutants.

S59: Compound-specific radiocarbon dating and its applications in biogeochemistry, sedimentology and paleo-environmental research

Conveners:	Gesine Mollenhauer	(gmollenhauer@rcom-bremen.de)
	Nao Ohkouchi	(nohkouchi@jamstec.go.jp)
Keynote:	Ann Pearson	(Harvard)

Since its development about a decade ago, compound-specific radiocarbon dating has provided new tools for the study long-standing questions regarding the cycling of organic carbon. Today, compound- specific and compound-class specific radiocarbon measurements are being applied in a variety of different environments to study diverse processes including microbial ecology, sediment transport, and soil residence times of terrestrial organic matter. We invite contributions from all fields of applications, including discussion of methodology.

S60: Organic imaging: biomarkers at the microscopic range

Conveners:	Volker Thiel	(vthiel@gwdg.de)
	Jan Toporski	(jan.toporski@witec.de)
Keynote:	Jürgen Popp	(Jena)

Recent developments in high-resolution imaging techniques have created enormous potential in the study of organic molecules in geobiological systems. Such techniques not only allow for the identification of biomarkers, they also provide a means to spatially resolve their distribution within the sample. Understanding the spatial distribution of specific marker molecules or biomarker categories at the sub-micron-resolution scale afford unprecedented insights into morphology - chemistry relations and contribute to better understanding geobiological processes and materials. Thus, organic imaging techniques have the potential to bridge the currently existing gap between conventional (i.e. extraction based) organic techniques, and inorganic or (electron-)optical approaches and, when used in conjunction, enhance analytical possibilities beyond standard laboratory routines. We encourage submissions that introduce, and highlight, the use of organic imaging techniques (e.g. ToF-SIMS, confocal Raman imaging, or MALDI-ToF-imaging) in the study of natural samples, and demonstrate how organic imaging can reveal a strong means to solving problems and testing hypotheses in geo- and astrobiology.

S61: Biogeochemical interactions in soils

Conveners:	Guido Wiesenberg	(guido.wiesenberg@uni-bayreuth.de)
	Roland Bol	(roland.bol@bbsrc.ac.uk)
Keynote:	W. Amelung	(Bonn)

This session will focus on biogeochemical processes and cycles in soils as the dynamic driving interface between atmosphere, biosphere and geosphere. Natural soil processes (including organic matter and nitrogen stabilization or gas flux dynamics) as well as anthropogenic influences (incorporation and stability of contaminants or agricultural amendments) will be addressed. Innovative approaches in the field of soil biogeochemistry using organic and/or inorganic geochemical techniques from element to molecular scale are welcome. Especially, contributions using bulk or compound-specific isotope techniques are invited, but not mandatory.

S62: Geochemistry of biominerals

Conveners:	Dorrit E. Jacob	(jacobd@uni-mainz.de)
	Anne L. Cohen	(acohen@whoi.edu)
Keynote:	Thomas Tütken	(University of Mainz)

Much of what we know about Earthís climate history comes from information stored within biogenic skeletons. While nucleation and growth of biogenic minerals are ultimately governed by the same physical controls as inorganic mineralization, they occur within a space and medium that is created, maintained and separated from the external environment by the organism. In addition, organic materials play an important role in the nucleation and growth of many biologically produced minerals. For these reasons, the morphology, crystallography and composition of crystals produced within biological systems may be quite different from those produced abiotically. Through advances in nanotechnology, molecular biology, and geochemistry, scientists across many disciplines are discovering and quantifying the factors that initiate and control nucleation, concentrations of constituent ions, regulation of growth, chemical composition, and shaping of complex morphologies. Advancing knowledge of these processes is paramount to the understanding of the geochemistry of biominerals and is the basis for using them as precise witnesses of the climate of the past. We invite papers from field, laboratory, and theoretical studies related to this rapidly developing research arena. The session is not restricted to biological systems. Papers reporting studies of abiogenic systems that are pertinent to understanding biomineralization processes are also encouraged.