Environmental geochemists at Penn State (Brantley, Fantle, Heaney, Ingalls & Lau) investigate the kinetics and the atomic-scale mechanisms that govern mineral-fluid reactions at the Earth’s surface. We also use geochemistry to trace anthropogenic influences on natural systems.
Examples of the kinds of problems that we study would include:
- Adsorption and sequestration of inorganic and organic contaminants in soils and sediments
- Aqueous complexation of metals with dissolved organic matter
- Stable isotope fractionation between minerals and solutions
- Dissolution and precipitation reactions of silica, feldspar, and metal (hydr)oxides
We approach these issues by striving to combine experiments, aqueous geochemistry, a range of modeling techniques, and synchrotron X-ray diffraction and spectroscopy in innovative ways.
The isotopic composition of Earth materials bear on all many geoscience questions, from the age of the continents, to the oxygenation of paleo-oceans, to the height of the (proto)Himalaya. Isotope geochemists at Penn State are at the cutting edge of both the development and application of isotopic tools to better understand the Earth. Profs. Reimink, Smye and Furman use laser-ablation, inductively-coupled plasma mass spectrometry (LA-ICP-MS), Thermal Ionization Mass Spectrometry (TIMS), and Secondary Ion Mass Spectrometry (SIMS) to determine the ages, sources, and thermal histories of a variety of rock and mineral samples. Profs. Fantle, Ingalls, Lau, and Lloyd use a slew of techniques to probe what the isotopic composition of carbonate and other sedimentary minerals record about their formation conditions and subsequent diagenetic histories. Prof. Freeman is a leader in development of groundbreaking methods for compound-specific isotope analyses, and Profs. Freeman, House, Baczynski, and Lloyd develop and apply proxies for climate and microbial metabolism and to characterize space organics using compound-specific and position-specific (i.e., isotopologues) isotopic compositions of organic molecules. Our lines of inquiry include:
- The temperature, pressure, and timing of metamorphic terrane formation
- The development of continental crust on the early Earth
- The evolution of lithospheric and asthenospheric reservoirs
- The biogeochemical response of Earth’s oceans to past intervals of environmental change
- How carbonate fabrics record the microbial activity that formed them
- How recrystallization and fluid flow preserve and alter isotopic records in marine sediments
- The environmental, biogeochemical, and metabolic records stored in organic molecules from living cells to ancient soils and sediments
- The sources, transformations, and fates of organic materials in space environments to inform understanding of prebiotic organics and potential biosignatures
CHEMISTRY AND PHYSICS OF ROCKS AND MINERALS
Several faculty in the Department of Geosciences work in the broad area of Physics and Chemistry of Rocks and Minerals. A primary focus is to unravel the mechanisms by which atomic-scale properties of Earth materials control large-scale geologic and geophysical processes.
Faculty in this area include Brantley, Fantle, Feineman, Furman, Heaney, & Lau. They are investigating the relationship between mineral chemistry, fluid-rock interactions and rock behavior using a variety of methods including:
- theoretical molecular modeling
- crystal structure analysis by synchrotron X-ray diffraction
- high resolution transmission electron microscopy
- reactive transport studies
- stable and radiogenic isotope analysis
- major and trace element microanalysis
- laboratory experiments at a range of pressures and temperatures
- novel fluid flow-through capabilities and chemistry
- mineral surface spectroscopy.
Geoscience Faculty work closely with Penn State Material Scientists and Geoenvironmental Engineers, and with the Materials Research Institute at Penn State, which features a wide array of state-of-the-art analytical instrumentation.
PETROLOGY AND VOLCANOLOGY
The Petrology and Volcanology group at Penn State (DiMaggio, Feineman, Furman, Reimink & Smye), explores the physical and chemical processes attendant to eruptive activity in a variety of tectonic settings, including active arcs, continental rifts and ocean islands. Their efforts integrate a range of techniques that encompass field work, SEM and TEM microanalysis, electron microscopy, image analysis, bulk rock analysis with DCP and ICP-MS, radiogenic isotope mass spectroscopy and direct low- and high-pressure experimentation.
Research in this area addresses fundamental questions that span a range of temporal and spatial scales, such as:
- What is the role of mantle plumes in continental rifting?
- How do magmatic and tectonic processes interact along plate boundaries?
- How do melt segregation and transport processes affect eruptive geochemistry?
- What is the role of subducted fluids in arc magma genesis?
- How can major explosive eruptions be predicted more accurately?
Faculty use an interdisciplinary approach, collaborating closely with geophysicists, chemists and computer scientists both at Penn State and around the globe.
RESOURCES AND FACILITIES
WHO WE ARE
Learn more about our research groups:
Dr. Kate Freeman’s research group studies organic molecules and their stable isotope signatures. We use fossil molecules, or biomarkers, derived from plants, microbes, and algae, to study Earth’s climate history, including carbon cycling in the ancient atmosphere and oceans, and the patterns of water, vegetation, and fire on ancient landscapes. Our group currently has a focus on new ways to measure isotopes within organic molecules (isotopologues) for biogeochemical and astrobiological applications and for space exploration. Kate is Director of the NASA Astrobiology Center for Isotopologue Research (ACIR) at Penn State, and is a participating scientist on NASA’s OSIRIS-REx mission. She is co-Director of the International Geobiology Course supported by the Agouron Institute and the Simons Foundation.
Dr. Max Lloyd’s group uses isotope geochemistry analyses to constrain interactions between life and Earth. We focus on the development and application of new isotopic measurements in organic molecules, especially isotopologue analyses (position-specific and clumped isotopes). Our geoscience questions are broad in scope, but we’re actively working on: i) plant-climate interactions, ii) deep biosphere microbial activity, and iii) the formation and alteration of organic molecules in space.
Dr. Matthew Fantle's research group utilizes novel metal isotopes, in conjunction with traditional isotopic systems, aqueous geochemistry, and various modeling techniques to develop new proxies, understand diagenesis at a process level, and interpret geochemical records of the past. Over the years, the Fantle group has contributed to characterizing the isotopic composition of fluxes in the geochemical cycles of a range of elements, including Ca, Fe, Mg, Li, and Sr, constraining the rates and impacts of carbonate diagenesis using isotopic tools, quantifying the impact of microbes on mineral isotopic composition, and investigating hyperthermal events in the rock record.
Dr. Miquela Ingalls and her research team use field geology, petrography, and stable isotope geochemistry to reconstruct the conditions (temperature, nutrient availability, hydroclimate) under which life evolved throughout Earth history, and how microbes influence the carbonate rock record. The Ingalls lab also studies how the chemical, textural, and isotopic features of carbonate rocks alter during early diagenesis and tectonic burial and unroofing to improve our ability to interpret sedimentary geochemistry in old rocks.
Dr. Peter Heaney’s group investigates mechanisms of crystal growth, dissolution, and transformation at the atomic scale through in situ synchrotron X-ray diffraction of mineral-fluid mixtures coupled with Rietveld analysis. Much of this work is directed towards the sequestration of dissolved metal ions by iron and manganese oxides in soil environments. Heaney’s exploration of gem materials has focused on unusual optical behaviors (e.g., asterism, iridescence) in microcrystalline silica (tiger’s-eye, agate) and iron oxide (hematite, goethite) varieties.
Dr. Kimberly Lau’s group uses the geochemistry of sedimentary rocks to understand biogeochemical and Earth system change. Integrating field, analytical, modeling, and experimental approaches across spatial scales, this work aims to improve interpretation of geochemical (including isotopic) proxies in carbonate and siliciclastic rocks. Additionally, research in our lab aims to understand fluid-rock interactions in the context of early diagenesis and in geochemical cycles (i.e., nutrients, continental weathering).
Dr. Tanya Furman’s group uses the petrology and geochemistry of igneous rocks to understand the geodynamic evolution of the planet. Their work integrates field observations with detailed textural and chemical analysis of mineral phases to address relationships between tectonism and magmatism in rift- and plume-related volcanic settings, as well as in complex compressional environments. Examples of analytical approaches include EPMA, LA-ICP-MS, crystal size distribution, isotopic analysis and precise age dating of volcanic products.
Dr. Jesse Reimink’s research group uses a blend of igneous petrology, geochronology, and isotope geochemistry to answer fundamental questions about the formation and evolution of Earth’s continental crust and planetary evolution. Their work entails fieldwork in remote locations where truly ancient continental crust is found, basic sample documentation and characterization, and using state-of-the-art geochemical techniques to determine the sources, ages, and overprinting histories of ancient tracts of continental crust. Current work is focused on determining why and when continents emerged above sea level, the geodynamic regime operative on the earliest Earth, and the amount of continental crust formed through time. Reimink’s research group manages the LionChron in situ geochron/geochemistry facility and uses other facilities on campus, Huck Institute, LIME, and collaborators laboratories across the world - Carnegie Geochemistry Facility, and the University of Alberta CCIM to name a few.