Student working in a labWe teach about how the earth works, inside and out. Whether to fulfill science distribution requirements, round out a background in physics or biology (or classics, or economics!), or to major in Geosciences, our Department has many topical and exciting courses.

We use our mountain setting as a natural lab. We spend time outdoors, looking at rocks in place and processes as they are happening. Whether assessing the flood potential of local streams, mapping the folded and faulted rocks of the Taconics or Green Mountains, studying Pleistocene glacial deposits, or collecting minerals or fossils, geosciences courses provide students with a wealth of enriching earth science experience.

Introductory Courses

Introductory courses are designed for any student wanting to know more about our home planet. Not just for prospective majors, these courses are broad overviews that give fascinating insight into how the earth works. There are no prerequisites, and all courses include field and lab work.

Upper-Level Courses

Upper-level courses focus on specific aspects of geosciences in greater depth. The 200-level courses are open to any student who has taken a 100-level geosciences course.

Note: Courses in gray are not available this year.

GEOS 101The Co-Evolution of Earth and Life

Not offered this year

Our planet is about 4.6 billion years old and has supported life for at least the last 3.5 billion of those years. This course will consider the inter-related nature of Earth and the life that inhabits it, starting with the first living organisms and progressing to the interaction of our own species with the Earth today. Students will investigate the dynamic nature of the Earth-life system, examine many of its feedbacks, and learn about the dramatic changes that have occurred throughout the history of the Earth. We will ask questions such as: How did the Earth facilitate biologic evolution, and what effects did those biologic events have on the physical Earth? When did photosynthesis evolve, how can we detect that in the rock record, and how did this biological event lead to profound changes in the environment? How and why did animals evolve and what role did environmental change play in the radiation of animal life? How did the rise and radiation of land plants affect world climate? How do plate tectonics, glaciation, and volcanism influence biodiversity and evolutionary innovation? What caused mass extinctions in the past and what can that teach us about our current extinction crisis? Labs will involve hands-on analysis of rocks, fossils, and real-world data as well as conceptual and analytical exercises; field trips will contextualize major events in Earth history and will help students learn to read the rock record. Through these investigations, the class will provide a comprehensive overview of Earth history, with special attention paid to the geological and paleontological history of the northeastern United States. [ more ]

GEOS 102(S)An Unfinished Planet

The Earth is a work-in-progress, an evolving planet whose vital signs--as expressed by earthquakes, volcanic eruptions, and shifting plates--are still strong. In a geological time frame, nothing on Earth is permanent: ocean basins open and close, mountains rise and fall, continental masses accrete and separate. There is a message here for all of us who live, for an infinitesimally brief time, on the moving surface of the globe. This course uses the plate tectonics model--one of the fundamental scientific accomplishments of the past century--to interpret the processes and products of a changing Earth. The emphasis will be on mountain systems (on land and beneath the oceans) as expressions of plate interactions. Specific topics include the rocks and structures of modern and ancient mountain belts, the patterns of global seismicity and volcanism, the nature of the Earth's interior, the changing configurations of continents and ocean basins through time, and, in some detail, the formation of the Appalachian Mountain system and the geological assembly of New England. Readings will be from a physical geology textbook, a primary source supplement, selected writings of John McPhee, and references about the geology of the Northeast. [ more ]

GEOS 103(F)Global Warming and Natural Disasters

The destruction caused by recent storms such as Irene and Sandy, devastation of prolonged drought in the African Sahel, catastrophic flooding and mudslides in SE Asia and sea level encroachment on the Alaska coast are visible examples of natural disasters that may be modulated by climate change. Global climate change, together with environmental degradation and the explosive growth of urban areas, has the potential to increase the severity and impact of natural disasters. In this course we globally examine geological and climatological processes that "set up" natural disasters such as hurricanes, floods, landslides, droughts, extreme temperatures, and coastal surges, as well as the processes that condition availability of water resources. We study in detail the causes and anticipated consequences of human alteration of global climate and its impact on the spectrum of natural hazards and resources. During laboratory sessions we use local field sites and computer models to analyze recent disasters/hazards, trends in weather and climate and options for mitigating future impacts. [ more ]

GEOS 104(S)Oceanography

The oceans cover about 72% of Earth's surface, yet we know the surface of Venus better than our own ocean floors. Why is that? This integrated introduction to the oceans covers formation and history of the ocean basins; the composition and origin of seawater; currents, tides, and waves; ocean-atmosphere interactions; oceans and climate; deep-marine environments; coastal processes; productivity in the oceans; and human impacts. Coastal oceanography will be investigated on an all-day field trip, hosted by the Williams-Mystic program in Connecticut. [ more ]

GEOS 201(F)Geomorphology

This course is designed for Geosciences majors and for environmental studies students interested in surficial geologic processes and their importance in shaping the physical environment. Geomorphology is the study of landforms, the processes that shape them and the rates at which surface processes change the landscape. This class emphasizes the influence of climatic, tectonic, and volcanic forces on landform evolution over relatively short periods of geologic time, generally thousands to a few millions of years. At this time scale, the influence of human activity and climate change on landforms may be strong, perhaps dominant, in many geologic environments. Many of our examples analyze human interaction - planned or unplanned-- with geomorphic processes. Labs focus on field measurements of channels and landscapes in the Williamstown area as well as on the analysis of topographic maps and stereo air photos. [ more ]

GEOS 202(S)Mineralogy

This course could be subtitled "An Introduction to Earth Materials and Analytical Techniques." As the basis for all subsequent solid-earth courses in the major, it provides a systematic framework for the study of minerals--Earth's building blocks: their physical and chemical properties at all scales and the common analytical methods used to identify and interpret them. The course progresses from hand-specimen morphology and crystallography through element distribution and crystal chemistry to the phase relations, compositional variation, and mineral associations within major rock-forming mineral systems. Laboratory work includes the determination of crystal symmetry; mineral separation; the principles and applications of optical emission spectroscopy; wavelength- and energy-dispersive x-ray spectrochemical analysis; x-ray diffraction; the use of the petrographic microscope; and the identification of important minerals in hand specimen and thin section. [ more ]

GEOS 205(F)Earth Resources

The metal in your soda can, the plastic in your Nalgene, the components of your computer, the glass in your window, the hydrocarbons being burned to keep you warm in the winter or to transport you in cars or aircraft, the cars and aircraft themselves: all are made of materials mined from the Earth. Right now there are more people building more houses, paving more roads, making more vehicles, more electronics, and more plastic packaging--all with geologic materials. As demand soars in both established and growing economies, and as we realize the environmental damage that can result from resource extraction and processing, the importance of understanding Earth's resources increases. Finding new deposits and managing those we have requires insight into the geology that underlies the location and origin of strategic Earth materials. This class introduces the geologic processes that control formation, distribution, and extent of materials reserves: dimension stone and gravel, base and precious metal ores, gemstones, petroleum, nuclear energy sources, and specialty materials for medical, technological, and military uses. [ more ]

GEOS 206Renewable Energy and the Sustainable Campus

Not offered this year

Rising oil and electricity costs disrupt the economy and help fuel global insecurity. Extraction of fossil fuels degrades the environment. Clearer understanding of how fossil-fuel consumption contributes to global climate change is increasing the demand for renewable sources of energy and for more sustainable campus environments. What sources of energy will supply Williams College and nearby areas in the twenty-first century? How will campus buildings, old and new, continue to be attractive spaces while making far more efficient use of heat and light? How can the College's operations and purchasing become more sustainable? This course is a practical introduction to renewable sources of energy, including conservation, principles of sustainability, and to their application to the campus environment. Topics covered include: biological sources of energy (biomass, biogas, liquid fuels), wind energy, geothermal and solar energy, energy efficiency and the environmental impacts of using renewable energy. Lectures, field trips and individual projects emphasize examples from the campus and nearby area. [ more ]

GEOS 210(F, S)Oceanographic Processes

This course examines ocean and coastal environmental science issues including carbon dioxide and the ocean's role in climate, El Ni?o and other ocean-atmosphere oscillations that influence our weather, coastal erosion and other hazards, coastal pollution, and fisheries. The focus is on controlling processes with regional comparisons. Blue water oceanography is conducted in the Atlantic and comparative coastal oceanography includes trips to southern New England shores, and the West and Gulf coasts of the US as part of the Williams-Mystic program. [ more ]

GEOS 212Paleobiology

Not offered this year

The fossil record is a direct window into the history of life on Earth and contains a wealth of information on evolution, biodiversity, and climate change. This course investigates the record of ancient life forms, from single-celled algae to snails to dinosaurs. In addition to the intellectual discovery of fossils as organic relics and the ways in which fossils have been used to support conflicting views on nature, geologic time, and evolution, we will cover a range of topics central to modern paleobiology. These include: how the fossil record informs our understanding of evolutionary processes including speciation; the causes and consequences of mass extinctions; how fossils help us tell time and reconstruct the Earth's climactic and tectonic history; statistical analysis of the fossil record to reconstruct biodiversity through time; analysis of fossil morphology to recreate the biomechanics of extinct organisms; and using fossil communities to reconstruct past ecosystems. Laboratory exercises will take advantage of Williams' superb fossil collections as well as published datasets to provide a broad understanding of fossils and the methods we use to study the history of life on Earth. We will also view a diversity of fossils in their geologic and paleo-environmental context on our field trip to Eastern New York. [ more ]

GEOS 214(S)Remote Sensing and Geographic Information Systems

This class provides a practical look at fast-evolving methods used to integrate information about the Earth's surface with spatial data collected by disciplines such as archaeology, economics, the field sciences, history and political science. Remote sensing involves collection and processing of data from satellite and airborne sensors to yield environmental information about the Earth's surface and lower atmosphere. Remote sensing allows regional mapping of rock materials, analysis of vegetation cover and measurement of urban areas and land-use change over time. A Geographic Information System (GIS) links satellite-based environmental measurements with spatial data such as topography, transportation networks, and political boundaries, allowing display and quantitative analysis at the same scale using the same geographic reference. This course covers concepts of remote-data capture and geographic rectification using a Global Positioning System (GPS), as well as principles of remote sensing, including linear and non-linear image enhancements, convolution filtering, and image classification. Principles of GIS include display and classification, spatial buffers, logical overlays and techniques of spatial analysis. Weekly labs focus on training in the application of techniques using data from the region and other areas of North America. [ more ]

GEOS 215Climate Changes

Not offered this year

In recent years, there has been a growing public and scientific interest in the Earth's climate and its variability. This interest reflects both concern over future climate changes resulting from anthropogenic increases in atmospheric greenhouse gases and growing recognition of the economic impact of "natural" climate variability (for example, El Ni?o events), especially in the developing world. Efforts to understand the Earth's climate system and predict future climate changes require both study of parameters controlling present day climate and detailed studies of climate changes in the past. In this course, we will review the processes that control the Earth's climate, like insolation, the greenhouse effect, ocean circulation, configuration of continents, and positive and negative feedbacks. At the same time, we will review the geological record of climate changes in the past, examining their causes. Laboratory exercises and problem sets will emphasize developing problem solving skills and using quantitative analyses to assess if a given explanation is possible and reasonable. These exercises will include developing and applying numerical models of the radiative balance of earth and the carbon cycle. [ more ]

GEOS 217 T(F)Planets and Moons

We live in a solar system full of wonders. Each planet and each moon is strange: different from our Earth, and different from each other. The recent flood of images and data from Mars constantly reveals new marvels--the rest of the solar system is even stranger. The U.S. put men on the moon; there are robots on Mars; and the Soviet Union landed several times on Venus. The other worlds are known only from flybys and remote images, but it's amazing how much those can teach us. By focusing on recent research, we will examine how the solar system works and delve into its mysteries. Topics may include the possible Late Heavy Bombardment of the moon, runaway greenhouse on Venus, water on Mars, hidden oceans on Europa, and the methane weather cycle on Titan. [ more ]

GEOS 226 TThe Oceans and Climate

Not offered this year

The oceans are a fundamental part of Earth's climate system. Ocean currents redistribute heat and water vapor around the globe, controlling temperature and precipitation patterns. Marine phytoplankton blooms and air-sea gas exchange modulate the atmospheric carbon dioxide concentration. The dynamic interaction of the atmosphere and the sea surface results in multi-year climate variations such as the El Ni?o-Southern Oscillation. This course will examine gradual and abrupt climate shifts from Earth's history and the ocean's role in driving, amplifying or dampening the changes, the ocean's response to anthropogenic greenhouse gas emissions, and the projected impacts of continued emissions and climate change on the ocean in the coming decades and millennia. We will analyze articles from the scientific literature that lay out the theory on the ocean's influence on climate, reconstruct past climate and ocean changes, test the mechanisms responsible for those changes, and with that knowledge, project the consequences of continued anthropogenic greenhouse gas emissions. Topics may include the climate effects of opening and closing seaways with plate tectonics, ocean feedbacks that amplify the intensity of ice ages, the instability of ocean circulation during ice-sheet retreat, the evolution of the El Ni?o-Southern Oscillation with changing carbon dioxide through the geologic past and the next century, ocean heat and carbon dioxide uptake during the last century and into the future, and the impact on sea level, seafloor methane reservoirs, ocean acidification, oxygenation and marine ecosystems. [ more ]

GEOS 254 T(S)Gulf of California Tectonics and Coastal Ecosystems

The coastal zone on Mexico's Baja California peninsula extends more than 1,000 km from northwest to southeast within the Gulf of California, but the composite length including indented bays and the circumference of more than 40 islands amounts to almost 3,000 km. The ecosystems developed along the shores of this tectonically active and expanding seaway include rocky shores, coastal sand dunes, coral reefs, clam beds, and huge banks of unattached coralline red algae known as rhodoliths. Sequestration of calcium-carbonate (CaCO3) is one factor that all the ecosystems share in common. The products of these limestone-producing systems are surprisingly monumental in physical scale, given the brief 5.5 Ma during which they evolved. Why are these systems so prolific and what physical factors control their biogeography within the context of each island, embayment, or headland? What role is played by changing climate, particularly with respect to patterns of atmospheric and marine circulation associated with El Ni?o Southern Oscillation (ENSO) cycles traceable back through the Pleistocene and Pliocene? These questions are holistic in scope, and the answers are deeply rooted in the wider region?s dynamic geological history. The tools used to answer such questions range from the petrographic microscope in examination of tiny bioclastic grains to satellite images in the analysis of landscapes. The object of this course is to demonstrate how a wide range of disciplines in physical geology, geomorphology, paleontology, and ecology combine to provide a broad but balanced picture of a complex region. While not mandatory, all participants are eligible for a 10-day field excursion to the lower Gulf of California near Loreto in Baja California Sur (Mexico) during Spring Break. [ more ]

GEOS 301(F)Structural Geology

The structure of the Earth's crust is constantly changing and the rocks making up the crust must deform to accommodate these changes. Rock deformation occurs over many scales ranging from individual mineral grains to mountain belts. This course deals with the geometric description of structures, stress and strain analysis, deformation mechanisms in rocks, and the large scale forces responsible for crustal deformation. The laboratories cover geologic maps and cross sections, folds and faults, stereonet analysis, field techniques, strain, and stress. [ more ]

GEOS 302(S)Sedimentology

Sediments and sedimentary rocks preserve information about the rocks that were eroded to form them, the fluids and forces that transported them, the mechanisms by which they were deposited, and the processes by which they were lithified. This course introduces the principles of sedimentology, including sediment composition, fluid mechanics, bedform analysis, and depositional environments. [ more ]

GEOS 303(F)Igneous and Metamorphic Petrology

Using plate tectonics and the geologic assembly of New England as a template, this course explores the origin of crystalline rocks--volcanic, plutonic, and metamorphic--that comprise 94% of the Earth's crust. Field and lab studies are the crux of the course, supported by experimental work and thermodynamic principles. Chemical and mineralogical compositions and rock fabrics provide evidence for crystallization environments and tectonic settings, past and present. [ more ]

GEOS 311Geobiology

Not offered this year

Geobiology-- the study of interactions between earth and life over geologic timescales--is a new and interdisciplinary field that has grown out of exciting advances in earth and life sciences. During this course we will explore the way in which life has shaped our planet over geological timescales. Topics include the origin of life, the rise of oxygen in the earth's atmosphere, the evolution of biomineralization, the environmental context for animal evolution, the role of microbial communities in the earth system, the emergence of land plants, and the potential for planet-life interactions elsewhere in our solar system, among others. Geobiology incorporates tools and ideas from geochemistry, paleontology, microbiology, and sedimentology. Labs will be varied and involve everything from growing our own microbial ecosystems and cyanobacterial mat communities to querying online databases and analyzing geological, geochemical, genetic, and paleontological data. Our field trip will take us to Harvard and MIT where we will tour labs doing cutting-edge geobiology research. The final project will involve literature-based research on a sub-topic of interest to the student within the field of Geobiology. The student will be responsible for an oral presentation at the end of the semester as well as mock grant proposal to study the area further. [ more ]

GEOS 314(S)Sediment Records of Climate Change

Sediments and sedimentary rocks may appear unassuming but they are an extraordinarily rich archive of Earth's geologic history, including Earth's past climate. In the first half of this class, we will survey techniques of stratigraphic analysis and dating of sediments, including paleomagnetism, seismic stratigraphy, biozones, and radioisotope methods. In the second half, we will survey the wide variety of methods for reconstructing past climate from sediments including the composition and texture of the sediment, the assemblage of fossils, and the elemental and isotope chemistry of sediment components. These are used to reconstruct many climatic parameters from the past, including the temperature and salinity of seawater, atmospheric carbon dioxide concentration, ocean circulation, sea ice distribution, global terrestrial ice volume, terrestrial biomes, and in some cases, seasonal to interannual climate variability. In labs and independent projects, students will apply these tools to a collection of sediment samples spanning eight million years from the warm Miocene to the present collected from the Monterey Bay region by GEOS 25 during WSP. Students who register for this class are strongly encouraged to take GEOS 25, and are given enrollment preference in that course. [ more ]

Taught by: TBA

Catalog details

GEOS 401(F)Global Tectonics and the Rise of Mountains

Fifty years after the sea-floor spreading hypothesis was first verified using magnetic anomalies, we have spectacular data sets from paleomagnetism, seismology, volcanism, the Global Positioning System, and digital elevation models that provide rich details into the kinematics and mechanisms of present and past plate motions. After an introduction to the theory of plate tectonics, local field trips will illustrate how field observations can be used to reconstruct tectonic environments in ancient mountain belts. We will learn how to use available CPS data to determine relative plate motions and how to portray them on Google Earth. Digital elevation models integrated with geologic maps and cross-sections will be used to construct 3D models. We will also explore ways in which tectonics, climate, and erosion affect each other during the evolution of mountain ranges. Class meetings will include lectures and discussions of assigned reading. Labs will include field trips and computer-based projects. [ more ]

GEOS 405(F)Geochemistry: Understanding Earth's Environment

Rocks, water, air, life: what comprises these interconnected components of the Earth system? How do they interact today, and how did these interactions differ in the past? In this course we will study how chemical elements are distributed in the Earth, cycle through the Earth system, and act together to produce a planet that is habitable. As Earth's landscapes and oceans, and the life they harbor, have evolved through time, they have left an imprint in the geological record that we can read using geochemical tools such as molecular fossils, elemental ratios, and stable and radioactive isotopes. Topics include the synthesis of elements in stars, the formation and differentiation of planet Earth; radiometric dating; the major constituents of the atmosphere, rain, rocks, rivers and the ocean; how they're linked by chemical weathering and biological activity; and reconstruction of past environments. Students will explore these topics through lecture; reading and discussing articles from the scientific literature; and collecting, analyzing and interpreting data from environmental samples. [ more ]