How The Discovery Of Geologic Time Changed Our View Of The World

This documentary describes the story in a very nice way. (http://www.youtube.com/watch?v=YpbevfWrYg0&feature=PlayL...)

This is an 8 part documentary. Well worth your time.

If you want more details I highly recommend the book that came along with the documentary. Earth Story. (http://www.amazon.com/Earth-Story-Forces-Shaped-Planet/dp/06...)

The article did not go into a lot of detail about how the development of the geologic timescale contributed to the science of geology. One of the most important contributions of the timescale was giving scientists a framework to correlate geologic events. For example the KT boundary groups the events of a mass extinction, elevated trace amounts of iridium, and the impact crater in Mexico. Before the timescale and radioactive dating, geologic events such as these were witnessed across the globe, but never correlated to be one single event.