A New “Golden Spike” Monument in Colorado Marks Geologic Time
blogs.kqed.org
For something that is supposed to keep track of 4 billion years of history, the geologic time scale is quite a fuzzy and slippery yardstick. After two centuries of careful research and argumentation, the world’s geologists have only recently adopted a system to literally nail down the different time periods taught in geology school. Last week that project took another slow step forward as a “golden spike” was officially driven into a precise spot on the ground near Pueblo, Colorado, a benchmark for the beginning of the Turonian Age.
