geochemistry DEPARTMENT

The Berkeley Lab Geochemistry Department’s scientists offer world-class expertise and wide-ranging research interests/activities in challenges facing the U.S. Department of Energy, the United States, and the world today. Activities address key societal needs, from contaminant fate and transport, alternative energy, carbon mitigation, to deep understanding of fundamental geochemical processes taking place in the Earth’s Critical Zone. Particular strengths of the department are reactive transport modeling, isotope geochemistry, molecular and nanogeochemistry, biogeochemical cycling, and water quality-energy issues.

Arora, Bhavna - Dr. Arora is a Research Scientist in the Energy Geosciences Division at Lawrence Berkeley National Laboratory. She received her Ph.D. from the interdisciplinary Water Management and Hydrological Science program at Texas A&M University in 2012. Dr. Arora also holds a minor in Mathematics and Computing from the Indian Institute of Technology, Kharagpur.

Christensen,John Neil - Dr. Christensen graduated from UC Berkeley with a BA in geology, and received his Masters and Ph.D. in geology from the University of California, Los Angeles. He did post-doctoral work at the University of Michigan’s Dept. of Geological Sciences and stayed on as research scientist before joining the LBNL Earth Sciences Division in 1999. In 2006 he became a staff scientist. John is an isotopic geochemist who uses MC-ICPMS and TIMS to develop techniques he uses in a wide variety of research, including basic science as well as problems in environmental science and environmental remediation.

Conrad,Mark S - Dr. Conrad received his Bachelor’s Degree in Geology from Pomona College in 1979, his Master’s Degree in Geology from Dartmouth College in 1982 and his Ph.D. in Geology from Harvard University in 1990. During that time, he also spent about 3 years total working in mineral exploration for several companies in Mexico, the western United States and Alaska. After a postdoctoral fellowship at Dartmouth College, he joined the Center for Isotope Geochemistry in the Earth Sciences Division at Lawrence Berkeley National Laboratory in 1992. In 2001, he became a Staff Geological Scientist and Head of the Geochemistry Department in 2006. His primary interests include using stable isotope measurements of groundwater and soil gas to identify areas of microbial activity, especially pertaining to bioremediation.

Deng, Hang - Dr. Deng is a Research Scientist in the Energy Geosciences Division, with research expertise in aqueous geochemistry and hydrogeology. Her research interests are (1) to advance fundamental understanding of the evolution of fractured porous media caused by coupled chemical-physical processes across scales and (2) to inform various subsurface practices (including geologic carbon storage) and to guide the resolution of pressing challenges regarding energy, water and environment. For her research investigations, she uses a suite of characterization techniques (e.g. high resolution microtomography), experimental tools (e.g. fracture flow experiment) and numerical models (e.g. computational fluid dynamics).

Dobson, Patrick - Dr. Dobson is involved in a variety of geologic and geochemical research projects. He ed LBNL’s efforts in the study of the Peña Blanca uranium deposits, a natural analogue for flow and transport processes at Yucca Mountain. From 2007 to 2009, he served as a detailee for the Geosciences Research Program of DOE’s Office of Basic Energy Sciences. He now leads LBNL’s Geothermal Systems Program.

DePaolo,Donald - Prof. DePaolo began his term in Berkeley in 1988 as a UC Berkeley Professor of Geochemistry in the Department of Earth and Planetary Science, with a joint appointment in the Earth Sciences Division at Berkeley Lab. DePaolo established and directs the Center for Isotope Geochemistry, a joint research facility between Berkeley Lab and UC Berkeley. DePaolo is also the Class of 1951 Professor of Geochemistry in UC Berkeley’s Department of Earth and Planetary Science. DePaolo was officially announced as the Earth Sciences Division Director in 2007. Prior to this appointment, DePaolo held the Geochemistry Department Head role in the Earth Sciences Division. In Spring of 2009, DePaolo became the Director of the Center for Nanoscale Control of Geologic CO2 (EFRC). DePaolo was appointed Associate Laboratory Director of Energy Sciences April 1, 2011.

Gilbert,Benjamin - Dr. Gilbert has made important contributions to the rapidly evolving field of nanogeoscience – the study of the properties and geochemical interactions of natural nanoscale minerals. Much of his research involves the development and application of synchrotron x-ray experiments and analysis methods for the study of mineral nanoparticles. Research accomplishments include: the discovery of stable cluster formation by iron oxyhydroxide nanoparticles; observation of structural transformations in ZnS nanoparticles associated with water binding; the identification of nanoscale silicate inclusions in zircons; and x-ray spectroscopic studies of the electronic structure of manganese oxides. More recently, his research has begun to apply ultrafast x-ray methods to study electron transfer to ferric iron oxide nanoparticles with sub-nanosecond temporal resolution. These studies are reported in more than 50 peer-reviewed publications that include collaborations with scientists from many disciplines.

Lammers, Laura - Dr. Lammers' research interests include environmental geochemistry, crystal growth, mineral-fluid and fluid-fluid interfacial processes, and contaminant transport.

Molins, Sergi - Dr. Sergi Molins is a research scientist in the Earth and Environmental Sciences at Berkeley Lab with extensive experience in the field of reactive transport modeling in porous media. His research focuses on elucidating processes affecting the formation of effective reaction rates at different spatial scales in subsurface applications relevant to energy and the environment. He currently investigates pore scale mechanisms controlling mineral dissolution rates in carbon sequestration scenarios (Molins et al., 2012, 2014b) and the role of microbial dynamics in natural and laboratory systems (Molins et al., 2014a; Druhan et al., 2012; Beller et al., 2014). He has also investigated the feedback mechanisms between biogeochemical reactions and gas transport in the vadose zone by means of the Dusty Gas Model (Molins and Mayer, 2007; Molins et al., 2008, 2010). Code development is an integral part of his work, having contributed to the reactive transport codes MIN3P (U. Mayer, UBC) and CrunchFlow (C. Steefel, LBNL). He has recently focused on the development of programming interfaces between existing geochemical codes and HPC simulators of flow and transport (Beisman et al., 2015, Alquimia), including Chombo-Crunch, a high-resolution reactive transport code for the direct numerical simulation of pore scale processes (Molins et al., 2012; Trebotich et al., 2014).

Nico,Peter S - Dr. Nico is a Soil and Environmental Biogeochemist who studies transition metal redox processes and their impact on the fate and transport of environmental contaminants. He also investigates soil carbon stabilization and mineralization mechanisms with an emphases on the role of mineral surfaces and redox active metals such as Fe and Mn. Much of his work uses synchrotron based X-ray spectromicroscopic techniques to probe chemical and physical heterogeneity on the micron and nanometer scale. Dr. Nico leads the Resilient Energy, Water and Infrastructure Program Domain n the Energy Geosciences Division.

Simmonds, Meagen - Dr. Simmonds' is a soil and ecosystem biogeochemist, modeler, and data scientist who works to ensure the long-term sustainability of ecosystems by informing best management practices, decision-making, and policy. Her research focuses on terrestrial ecosystem processes, including land-atmosphere exchange of greenhouse gases (CO2, CH4, N2O). Predicting the interactive effects of climate, wildfire, soil and plant properties, and land management have been central themes in her work.

Sonnenthal,Eric - Over twenty years experience in the study of coupled thermal, chemical, transport, and mechanical processes and the development of reaction-transport models and codes. Obtained a Ph.D. in Geological Sciences at the University of Oregon focused on the geochemical and physical processes associated with volatile evolution and melt segregation in basaltic lava flows/lakes and in the Skaergaard Intrusion, East Greenland. This started an interest in the coupling of geochemical reactions with fluid transport and deformation which led to postdoctoral work at Indiana University and the French Institute of Petroleum on modeling the development of overpressured compartments in sedimentary basins through coupling of sedimentation, pressure solution compaction, fluid flow, heat and chemical transport, and hydrofracturing. Since coming to Berkeley Lab in 1996, worked on modeling the geochemical and hydrological evolution of the unsaturated zone at Yucca Mountain, and led the development of coupled thermal-hydrological-chemical models for the geologic emplacement of nuclear waste and in-situ thermal experiments. Current projects involve development of coupled thermal-hydrological-mechanical-chemical (THMC) models for enhanced geothermal systems, integration of isotopic systems in reaction-transport modeling of microbially-mediated environmental remediation, and leading an NSF-supported project to design a potential coupled process experiment in the Deep Underground Science and Engineering Lab in the Homestake Mine, South Dakota. Co-developer of the widely-used reaction-transport code Toughreact, as well as author of reaction-transport codes for magmatic differentiation and sedimentary basin evolution.

Spycher,Nicolas - Nic Spycher's specific research areas include water/rock interactions in geothermal systems and geothermal exploration, the impact of CO2 geological sequestration on groundwater quality, U(VI) transport and reactive chemistry at contaminated DOE sites, metal cycling in contaminated lake sediments, and the study of coupled thermal, hydrological, and chemical processes related to nuclear waste geologic storage. He has also been working on the development of chemical geothermometry software (GeoT), gas solubility correlations for carbon dioxide sequestration and geothermal studies, and has developed and compiled thermodynamic data for use with geochemical models, including the aqueous speciation and surface complexation of various metals. He is part of the TOUGHREACT reactive transport simulator development team and has significantly contributed to the development of the CHILLER/SOLVEQ geochemical modeling codes. Besides his academic background, Nic has extensive experience in the field of environmental hydrogeology and hydrogeochemistry, including ten years of private-sector consulting experience dedicated to the remedial investigation of contaminated sites. His investigations included predicting the fate of metals, spilled fuels, and solvents in the subsurface using various field measurements and modeling techniques.

Steefel,Carl I - Dr. Steefel has over 27 years of experience in developing models for multicomponent reactive transport in porous media and applying them to topics in reactive contaminant transport and water-rock interaction. He developed the first routine for multicomponent nucleation and crystal growth in the Earth Sciences (Steefel and Van Cappellen, 1990) and the first multicomponent, multi-dimensional code for simulating water-rock interaction in non-isothermal environments (Steefel and Lasaga, 1994). He has also worked extensively in applying reactive transport modeling to natural systems, including hydrothermal, contaminant, and chemical weathering environments. Recently, he has been involved in experimental studies of cation exchange (Steefel et al., 2003) and mineral dissolution and precipitation (Yang and Steefel, 2008), as well as modeling studies of field systems focused on contaminant transport, microbially-mediated biogeochemical reactions, chemical weathering (Giambalvo et al., 2002; Steefel, 2004; Maher et al., 2009; Li et al., 2009), and isotope systematics (Druhan et al., 2012; Steefel et al., 2014). More recent work has focused on pore scale studies, including those using high performance computing (Li et al, 2008; Molins et al., 2012, 2014; Steefel et al., 2015). He is the principal developer of the reactive transport software CrunchFlow (Steefel et al, 2015).

Stolper,Daniel Aaron - Dr. Stolper is a geochemist who investigates a variety of problems related to the rock record, microbiology, and biogeochemical cycles in the present and past. His approach to scientific problems centers on linking experiments and physically based models to natural observations in an integrated fashion and, when necessary, developing new methods and techniques. His lab work focuses on mass spectrometric measurements of experimental and environmental samples.

Stringfellow,William T - Dr. Stringfellow is a Professor and Director of the Ecological Engineering Research Program at the School of Engineering & Computer Science at the University of the Pacific in Stockton, CA. He also has a joint appointment with the Geochemistry Department, Earth & Environmental Sciences Area at Berkeley Lab, CA. He received his B. S. in Environmental Health from the University of Georgia (Athens, GA) in 1980 and his Master’s Degree in Microbial Physiology and Aquatic Ecology from Virginia Tech (Blacksburg, VA) in 1984. He received his Ph.D. in Environmental Sciences and Engineering from the University of North Carolina at Chapel Hill in 1994 and worked as a Post-Doctoral Fellow in the Civil and Environmental Engineering Department at the University of California at Berkeley.

Varadharajan, Charuleka - As a biogeochemist and environmental data scientist, Charu is interested in the water, energy and carbon nexus to understand and limit the impacts of human activities on water resources and climate. Her research has previously involved studying the fate, transport and mitigation of contaminants in groundwater; measurement and prediction of carbon fluxes in terrestrial and subsurface environments; and management, synthesis, and analysis of diverse multi-scale environmental datasets.

Woodburn,Erica Rachel - Dr. Erica Siirila-Woodburn is a Research Scientist in the Energy Geosciences Division at Lawrence Berkeley National Laboratory. She received her Ph.D. from the Colorado School of Mines in 2013 and was a postdoctoral researcher at the Polytechnic University of Catalunya before joining LBNL in 2015. A hydrogeologist by training, her research takes an interdisciplinary approach to understanding physical, ecological, and geochemical solute transport processes across many spatial scales. Her research is focused in the fields of integrated groundwater-surface water hydrology, stochastic approaches and geostatistics, risk analysis, and numerical techniques. She is currently interested in enhancing LBNL’s environmental data capabilities towards building an environmental knowledgebase, in partnership with the Computational Research Division