Portland Community College | Portland, Oregon

Earth Surface Processes (G 202) is intended for both geology majors and non-majors, and is one term of a three course group of foundational college geology courses.  G 202 examines  the Earth's landscapes and the geologic processes which create landscapes.

Students are expected to be able to read and comprehend college-level science texts and perform basic mathematical operations in order to successfully complete this course.

Earth and space sciences are based on observations, measurements and samples collected in the field. Field-based learning is recommended by numerous professional Geology organizations, including the American Geological Institute and the National Association of Geoscience Teachers. Field-based learning improves both metacognition and spatial/visualization abilities while helping to transfer basic concepts to long-term memory by engaging multiple senses at the same time. Spatial thinking is critical to success in STEM (Science, Technology, Engineering, and Math) disciplines. Field work may include:

• Developing skills in site characterization
• Application of key terms and concepts
• Measurement and data collection
• Interpretation of data and observations, and fitting them to a larger context

Field work may be physically challenging and may require overland travel on foot or other means to field sites, carrying equipment and supplies, and making measurements in unusual or awkward positions for a length of time.  Field work may include inherent risks (uneven terrain, variable weather, insects, environmental irritants, travel stress, etc.). Field work can be adapted to individual abilities.

Regarding the teaching of basic scientific principles (such as geologic time and the theory of evolution), the Portland Community College Geology/General Science Subject Area Committee  stands by the following statements about what is science. 

• Science is a fundamentally non-dogmatic and self-correcting investigatory process. A scientific theory is neither a guess, dogma, nor myth. The theories developed through scientific investigation are not decided in advance, but can be and often are modified and revised through observation and experimentation.
• “Creation science,” also known as scientific creationism, is not considered a legitimate science, but a form of religious advocacy. This position is established by legal precedence (Webster v. New Lenox School District #122, 917 F.2d 1004).
• Geology/General Science instructors at Portland Community College will teach the generally accepted basic geologic principles (such as geologic time and the theory of evolution) not as absolute truth, but as the most widely accepted explanation for our observations of the world around us. Instructors will not teach that “creation science” is anything other than pseudoscience.
• Because “creation science”, “scientific creationism”, and “intelligent design” are essentially religious doctrines that are at odds with open scientific inquiry, the Geology/General Sciences SAC at Portland Community College stands with such organizations as the National Association of Geoscience Teachers, the American Geophysical Union, the Geological Society of America, and the American Geological Institute in excluding these doctrines from our science curriculum.

Upon completion of the course students should be able to:

1. Explain the geologic processes which formed specific landforms using an understanding of landform characterization and classification.
2. Analyze how earth materials, uplift, subsidence, erosion, transport, deposition, climate, biological activity, and time interact to create landscapes.
3. Evaluate an earth surface processes-related problem or issue impacting our community or the environment using scientific reasoning based on field and/or laboratory and/or remote measurements and observations. 
4. Assess the contributions of physical geology to our evolving understanding of global change and sustainability while placing the development of physical geology in its historical and cultural context.

The material in this course will be presented in a  lecture/discussion format accompanied by laboratory exercises. Other educationally sound methods may be employed such as guest lectures, field trips, research papers, presentations, and small group work.

At the beginning of the course, the instructor will detail the methods used to evaluate student progress and the criteria for assigning a course grade. The methods may include one or more of the following tools: examinations, quizzes, homework assignments, laboratory write-ups, research papers, small group problem solving of questions arising from application of course concepts and concerns to actual experience, oral presentations, or maintenance of a personal work journal.

1. Identify and classify the landforms associated with mass wasting, groundwater, streams, glaciers, deserts and shorelines
2. Understand how landforms are related to the processes of erosion, transport and deposition
3. Describe the materials that make up landforms associated with mass wasting, groundwater, streams, glaciers, deserts and shorelines
4. Examine weathering and the formation of soils (this topic may be covered in either G201 or G202 at the discretion of the instructor)
5. Develop an understanding of the kinds and origins or geologic structures (this topic may be covered in either G201 or G202 at the discretion of the instructor)
6. Examine the role of plate tectonics in shaping the surface of the Earth
7. Discuss hazards associated with mass wasting, groundwater, streams, glaciers, deserts and shorelines

Topics to be covered include: 
 

1. Weathering (may be taught in G201 instead)
   1. Mechanical weathering (frost wedging, abrasion, exfoliation)
   2. Chemical weathering (dissolution/solution, oxidation, hydration)
   3. Factors that affect weathering rates
   4. Products of weathering (sand, clay, iron oxides/hydroxides)
   5. Soil structure
   6. Types of soils (pedocals, pedalfers, laterites)
2. Structural Geology (may be taught in G201 instead)
   1. Stress and strain
   2. Folds (syncline, anticline, dome, basin)
   3. Faults (normal, reverse, strike-slip)
   4. Strike and dip
   5. Mountain building and relation to stress
   6. Relationship to plate tectonics
3. Mass Movement
   1. Causes of mass movement (gravity, slope angle, angle of repose, slope composition, vegetation, water)
   2. Types of mass movement (falls, flows, slides, slumps)
   3. Features associated with mass movement (talus, evidence of creep, scarp)
   4. Prevention of mass movement
   5. Triggers (storms, earthquakes, fires, land use)
4. Streams
   1. Hydrologic cycle
   2. Stream topography (drainage basin, divide, tributaries, distributaries, gradient, graded stream)
   3. Stream erosion (base level, abrasion, hydraulic lifting, dissolution, waterfalls)
   4. Drainage patterns (dendritic, radial, rectangular, trellis)
   5. Channels (braided stream, meandering stream, cut bank, point bar, flood plain, terraces)
   6. Transport (competence, capacity, dissolved load, suspended load, bed load, saltation)
   7. Deposition (alluvial fan, delta, channel deposits, flood plains)
5. Groundwater
   1. Groundwater movement (hydraulic gradient, zone of aeration, zone of saturation, water table, porosity, permeability, aquifer, aquiclude, artesian systems)
   2. Springs and geysers
   3. Groundwater pollution/depletion (subsidence, saltwater intrusion, cone of depression)
   4. Karst topography (sinkholes, bind valleys, disappearing streams)
   5. Caves and their features (stalactites, stalagmites, soda straws, columns, dripstone/flowstone)
6. Glaciers
   1. Formation and budget of glaciers (snow to firm to glacial ice, zone of ablation/wastage, zone of accumulation, furn line/snow line)
   2. Classification of glaciers (alpine glaciers, valley glaciers, continental ice sheets)
   3. Glacial flow (plastic deformation and basal slip)
   4. Erosional features (cirque, tarn, horn, arête, u-shaped valley, hanging valley, fjord)
   5. Glacial sediments and sedimentary features (drift, till, erratic, moraine, drumlin, outwash, eskers)
   6. Introduction to ice ages (evidence for past ice ages, possible causes of last ice ages)
7. Deserts
   1. Types of deserts (subtropical created by global air circulation, rain-shadow)
   2. Water erosion and deposition and related features (alluvial fan, pediment, bajada, arroyos, playa)
   3. Wind erosion and deposition and related features (deflation, deflation basins, desert pavement, ventifacts, yardangs, dunes, loess)
8. Coasts
   1. Waves (wavelength, wave base, wave motion, breaker, wave refraction, longshore current, rip current)
   2. Erosion and erosional features (headlands, wave-cut platform, marine terrace, sea cave, sea arch, sea stack)
   3. Deposition and depositional features (beach, spit, berm, baymouth bar, tombolo, groins, jetties, breakwaters, barrier islands)
   4. Relationship to plate tectonics (passive vs. active margins)
   5. Features associated with sea level changes (estuary, fjord)
   6. Causes of sea level changes (glaciers, rate of sea-floor spreading, human-induced global warming)