Anatomy of a Continent - Lesson 20 - Part 1 of 6

Planet of Man Series -- Shield of Plenty Intro - Dr. David Pearson Starring; Tuzo Wilson -- renowned geophysicist Anatomy of a Continent-Lesson 20-Part 1 of 6 Planet of Man -- Shield of Plenty •Typical topography of Northern Ontario and northern Canada •Canada's wealth is found in the shield •Precambrian characteristic -- red, granitic & contorted •Oldest rock in the world - precambrian •Cambrian name derived from rocks found in Wales that are .5 billion years old •Grenville rocks formed about 1 billion years ago •Mining footage from the 1960's -- showing headframes, blasting in open pits and underground •17% of earth is made of Precambrian shield; Canadian Shield, South American Shield, Indian Shield, Baltic, African, Australian •Shields are hard to live in and difficult to penetrate •Precambrian rocks found at bottom of canyons - Grand Canyon •Precambrian rocks found at base of mountains -- New Mexico •Geological time -- Precambrian time -- scale showing time •20th century idea of age of the earth-- 1917; earth age 1 billion, 1947; 3 billion years old today 4.5 billion years •Precambrian rocks still being studied and researched.