Jason McGill Outline Physical Geology Speech 1 Grand Canyon I. About the Grand Canyon, the history of the Canyon and Geologic Story of the Canyon A. Attracts attention of world for many reasons, but greatest significance lies in the geologic record preserved and exposed here.
1. What is unique is the variety of rocks present, clarity with which they are exposed and complex geologic story they tell.
B. Two separate stories exist at Grand Canyon 1. Older story is the one revealed in the thick sequence of rocks exposed.
a. Rock provide remarkable record of the Paleozoic Era b. Show that the rocks of the Canyon are much more older than the rocks itself.
2. Second story concerns origin of Canyon itself: when and how did it come to be? a. Erosional feature that owes it existence to the Colorado River.
b. Equal importance goes to forces of erosion that have shaped and continue to shape Canyon today.
1. i.e., running water from rain, snowmelt and tributary streams.
C. How old is the canyon itself? history and evolution of Colorado River is most complex aspect of Grand Canyon geology 1. Know that erosion shaped which has shaped canyon occurred only in the past five to six million years.
D. Lets talk about some basic facts of the canyon, as you know, the canyon is located in Colorado hovering over the Colorado River.
E. After thousands of years of Native Americans in southwest, first Europeans arrived at Canyon's South Rim in 1540 1. Following 300 years of missionaries, trappers, explorers, govt. surveyors and soldiers roaming the land, A major named John Powell and his crew made the first ever successful boat trip down to Colorado river through the canyon in 1800.
a. This triggered the drawing of visitors and businessmen alike...