VIEWING THE GEOLOGIC TIMELINE FROM THE PERSPECTIVE OF INTEGRATED SCIENCE

Construction of a geologic timeline is a common activity in K-8 classrooms and in the training of preservice teachers. The procedure is well described in Teaching about Evolution and the Nature of Science (National Academy Press, 1998). The activity is commonly viewed through the prism of biology with fossil organism displayed across the spectrum of geologic time. We have developed complimentary timelines that emphasize the significant events of and interconnectedness between the atmosphere, solar system, and geosphere. Some key conditions/events/processes we feature include: differentiation of the Earth; formation of the Moon; changes in cratering rates; early, nitrogen-rich atmosphere; volcanism on the Moon; oldest mineral, rock, and fossil; geologic evidence of atmospheric composition; gradual increase but low abundance of oxygen; presence of ozone and abundant oxygen as life emerges onto land; coalescence and dispersal of Columbia, Rodinia, and Pangaea supercontinents and resultant effects on species distribution; impacts; mass extinctions; Ice House and Hot House climates; and high carbon dioxide levels. We will present results assessing if the activity encourages a more holistic view of the Earth history.