Course 12.710 Introduction to Marine Geology and Geophysics Fall, 2007 Instructors: Dan Lizarralde Jerry McManus Ken Sims TAs: (WHOI, Clark, 260, x 2942, danl@whoi.edu) (WHOI, Clark 121, x3328, jmcmanus@whoi.edu) (WHOI, Clark 247B, x2634, ksims@whoi.edu) Lynne Elkins (WHOI, Clark 259 , x3422, lelkins@whoi.edu) Class Times, Places: Lectures – Tue./Thurs 10:30-12:00, Clark237 Labs/Discussion Sections – Time TBD Course Description: An introduction to marine geology and geophysics for non-majors Topics include the geologic time scale, structure of the Earth, plate tectonics, marine sedimentation and stratigraphy, depositional and erosional processes, submarine morphology, paleoceanography, sea level changes and the evolution of the Mesozoic-Cenozoic global ocean and climate This course is intended for non-G&G students as a single semester course There will be two 1/2 hourlong lectures each week Problem sets will be regularly assigned and there will be weekly discussion sections and occasional labs during the semester Text/Readings: Because of the breadth of topics covered there is no single textbook that is adequate for the purpose Lecture notes will be distributed for each class along with reading assignments in several relevant textbooks placed on reserve or in journals Students are responsible for the material covered in both the lectures and the reading Grading: Mid-term exam - 25% Final exam - 25% Labs/Problem Sets - 50% Geophysical Methods and Observations 10/25 (Lizarralde) Seismology: Earthquakes and Earth imaging 10/30 (Lizarralde) Potential fields, electro-magnetics, linear inverse theory 11/1 Mid Term Sediments and Sedimentary Processes 11/1 11/6 11/8 11/13 (McManus) (McManus) (McManus) (McManus) Fluvial and coastal sedimentation Marginal sedimentation, sequence stratigraphy Deep-sea sediments: composition, distribution Biological, chemical, and physical abyssal processes Paleo-oceanography and Climate 11/15 (McManus) Dating methods and the sedimentary record 11/20 (McManus) Paleothermometry 11/22 Thanksgiving 11/27 (McManus) Deep water chemistry and atmospheric p(CO2) 11/29 (McManus) Ocean chemistry and continental weathering 12/4 (McManus) Astronomical climate theory 12/6 (McManus) Sedimentary records of abrupt climate change 12/11 Final Exam Deep-Sea Sediments I Sources *1 Continents (dissolved, particulate) Submarine Extraterrestrial II Transport Wind (eolian) Ice Water Gravity III Composition Biogenic (opal, CaCO3, Corg) Lithogenic (clastic) Authigenic (inorganic precipitates) IV Distribution influences: Proximity of source (size) Depth of sea floor (CaCO3) Seawater chemistry (opal, CaCO3) Sedimentation rate (opal, Corg) vs Accumulation Dust Volcanic eruptions Hydrothermal input Black smoker vents (NOAA) Water (riverine, currents) Amazon discharge (NASA) Wind (eolian) Sahara Dust (NASA) Ice (glaciers, sea ice, icebergs) Clay type varies by weathering regime Chlorite ~ physical Kaolinite ~ chemical > 10 Biogenic sediments a) b) c) d) Coccoliths Foraminifera Diatoms Radiolarians Organic carbon Highly recycled: Preservation due to high productivity and rapid burial Opal deposits Highly recycled: Preservation due to high productivity and rapid burial Ocean distributes CaCO deposits Influenced by: Productivity and seawater chemistry, ocean circulation Carbonate content (after D Archer)) Intra-basin ocean circulation Biology and Physics influence Chemistry Circulation sweeps nutrients toward the Pacific, and productivity tends to trap them there From Atlantic to Pacific Ocean: Oxygen declines and silica increases in the deep water CaCO more soluble in the deep ocean: Pressure effect combines with lower [CO3=] The (“older”) deep Pacific is more corrosive Pressure effect combines with lower [CO3=] “Delta carbonate” (∆ CO3=) is defined as difference from saturation (after Broecker) Sedimentary sequence evolves through time Sediment cores will reflect that evolution, and can be used for reconstruction