ABSTRACT
Until the turn of the twentieth century, most scientists and geologists believed that the planet's continents were stationary. Scientists now know that Earth's crust is quite active, with fifteen larger plates pushing in at least twenty different directions. North America is moving west, South America is moving north, Europe and Asia are traveling east, and the Atlantic Ocean is growing, while the Pacific Ocean is shrinking. As the Himalayas and Southern Alps grow, the Alps and Rockies are shrinking. Change is the only constant in mountain formation. James Hutton, a Scottish geologist, studied granite and meta-morphic rock patterns of varying ages in his home country's coastal highlands. The next noteworthy advancement in geology came from William Smith, an English geologist who produced extensive surveys of Great Britain's geologic history. It took scientists a century to form a geologic timescale. Lengths of time were divided into five categories: eons, eras, periods, epochs, and stages.
