ANTARCTIC SEDIMENT CORE INTERPRETATION: EXERCISES THAT EXAMINE THE ‘HOWS' AND ‘WHYS', WHILE BUILDING STUDENT SKILLS AND KNOWLEDGE

This set of undergraduate student-active learning exercises focuses on the status and role of Antarctica in Cenozoic climate change, and builds skills and knowledge required to evaluate sediment cores retrieved from the floor of McMurdo Sound by the ANDRILL Project. Students discover new advances in understanding late Neogene Antarctic glacial history based on recent ANDRILL results. These exercises are part of the larger suite of activities in the project “Building Core Knowledge and Reconstructing Earth History”, which use authentic data to teach foundational concepts of climate change through sediment core archives (NSF Grant # 0737335).

The Antarctic exercises involve a review of the composite benthic foraminifer oxygen isotope curve, and of global climate interpretations based in part on this record. Basic geographic and geologic knowledge of Antarctica and cryospheric processes is constructed in order to build the rationale for selecting drillsites in McMurdo Sound. Student attention is then focused on the use of sedimentary facies and depositional environments in core interpretation, with particular attention to the facies associations that are diagnostic of ice-proximal and ice-distal settings in high latitudes. This is constructed through diagrams, geological reasoning, use of core images and core logs, and culminates in the construction of models for ice-retreat and ice-advance sequences. The general climate record of the entire ANDRILL 1-B core log (1285 m) is then interpreted, by characterizing each of the key lithostratigraphic sub-units in terms of the dominant depositional environments represented. Students write a brief history of the late Miocene-Pliocene climatic and environmental conditions in the Ross Sea region. Students conclude by evaluating facies patterns in the ANDRILL 1-B Pliocene sequence completing calculations that lead to interpretations of orbitally paced Pliocene ice sheet oscillations.