How did North America form? To answer this question, Kirk Johnson
, the Sant Director of the Smithsonian National Museum of Natural History, takes the viewer on an odyssey of time and space, from earth’s origin to the episodes of geologic history that pieced together the North American landmass. In this high interest video, the first episode of a three-part series, major events in earth history are discussed in a relevant and dramatic manner. Dr. Johnson conveys a sense of wonder and provides an enthusiastic introduction to mind expanding vistas of deep time and dramatic episodes in the story of North America.
At the Grand Canyon, layers of rock reveal past marine and desert climates that were once present in today’s southwestern United States. The Hawaiian Islands reveal a scene like that of the early earth with flowing lava forming new land. In a mine located a half-mile beneath the earth, palladium is mined from 3-billion-year-old rocks. Outcrops of basaltic lava in Minnesota point to a time when Laurentia, the proto-North America, nearly rifted apart. Later, the Manhattan schist in Central Park serves as evidence of an ancient continental collision. The formation of megacontinent Pangaea is demonstrated by the dramatic sandstone cliffs of Zion Park in Utah. Episodes in the orogenic uplift that formed today’s Rocky Mountains are evidenced by nearly vertical, dramatic fingers of red sandstone jutting forth from a Colorado golf course. Along the coast of Alaska, Dr. Johnson and a team of fossil hunters unearth fossils of tropical palm trees, evidence of the accretion process whereby fragments of land adhered to the western edge of North America. Near San Francisco, the San Andrea Fault emerges as a linear slice of earth forming Tomales Bay, and suggests a future where San Francisco and Los Angeles will become suburbs of each other due to the relentless, steady grinding of earth’s plates.
The PDF contains a two-sided video worksheet consisting of 43 multiple choice and true-or-false questions, and a sorting question whereby the students place the events in the formation of North America in order from the beginning to the present. The PDF also includes an answer key and an MS Word download link. You will need to obtain a DVD of the video, use the PBS Internet site, or YouTube