Program in Geology, Geochemistry, & Geobiology

Professor Tanja Bosak, Chair
Degrees Offered: S.M., Sc.D., Ph.D.

As scientists have started to recognize the fundamental evolutionary relationships among the continents, oceans, and atmosphere, the traditional disciplinary boundaries between the earth, atmospheric, and planetary sciences have dissipated. The Program in Geology, Geochemistry, and Geobiology (PGGG) at EAPS combines these sciences in order to develop more accurate monitoring, measuring, and imaging tools that will help us trace the history of Earth’s crust and its systems, thereby enabling us to better predict its future.

Although our scientists share many overlapping interests, we break ourselves into the following five categories:

Tectonics – In tectonics, we study how the Earth’s complex systems—beginning with its crust and upper mantle—influence each other as matter and energy are transferred among them. We seek to answer such questions as: What roles do climatic processes play in the development of mountain ranges? What is the nature of the interactions between crust and mantle, and how have these interactions influenced the development of each over time? With research that spans the range of geologic time, our faculty and scientists also explore the effects of surface processes on the development of mountainous terrains; develop tomographic images of the deep mantle to discover clues to the fate of lithospheric plates at convergent boundaries; and investigate active tectonics in the Mediterranean and Aegean regions. Our world-renowned expertise and collaborations involve aqueous geochemistry, geodesy, geodynamics, geomorphology, igneous and metamorphic petrology, isotope geochemistry, nonlinear dynamics, paeloclimatology, sedimentology, seismology, and structure geology.

Geochemistry and Petrology – The geochemistry and petrology group studies the conditions, timing, and rates of igneous and metamorphic processes in the Earth and other planets. Our interests include core formation in planetary interiors, magma generation at mid-ocean ridge, subduction zone and hot spot volcanoes, processes of chemical differentiation in the Earth’s mantle, and formation and modification of the Earth’s crust. With access to state-of-the-art analytical facilities that include thermal ionization and gas source mass spectrometers, electron and ion microprobes, multiple-collector ICPMS, and an experimental petrology laboratory, our students conduct their research in a collaborative atmosphere that encourages interdisciplinary approaches. Developing expertise in seismology, petrology, geology, and geochemistry, they work to integrate field observations and laboratory studies, developing a deep understanding of planet-forming processes.

Sedimentary Geology – Students of sedimentary geology study the complex interactions that shape modern Earth surface environments in order to better understand the geologic history of the continents and the oceans. Our studies are relevant to some of society’s most pressing concerns, including fossil fuel reserves, water supplies, and the effects of human influence on the natural environments in coastal areas, wetlands, and river systems. Due to our Reservoir Science Visualization Laboratory, our group is at the forefront of digital geology science, developing a greater understanding of reservoir architecture through the analysis of field analogs in order to merge quantitative geological information into seismic images of petroleum reservoirs.

Geobiology – The geobiology group studies surface processes and organic matter from microbes, environmental samples, and rocks. Our main focus is on the molecular biomarkers and stable isotopic signatures found in ancient materials like rock and oils. These tracers provide information about biogeochemical processes including photosynthesis, respiration, the methane cycle, and others. By identifying and studying the molecular and isotopic information, we can reconstruct ancient environments and discover patterns of Earth’s evolution. The interaction of the geosphere and biosphere—the field of geobiology—can help us learn about the history of oxygenic photosynthesis, which may have begun 3 billion years ago and which led to the appearance of animal life on earth.

Surface Processes – Our students investigate the production, delivery, transport, and deposition of sediment—the processes that drive the rock cycle and shape the Earth’s landscapes. Research topics include weathering, hillslope erosion and transport, sediment delivery to channels, surface hydrology, open channel flow, sediment transport, river incision, and morphodynamics. We study the interaction of surface processes with tectonics and climate at all scales, and we apply this knowledge in order to interpret the evolutions of both terrestrial and submarine landscapes. This field is of particular interest to students who want to study environmental land management, natural hazards, and exploration geology.