ESS105H1 Lecture Notes - Lecture 8: Metamorphic Rock, Arthur Holmes, Geiger Counter
Document Summary
Lecture 8: geological time & geological history of canada. James hutton is the pioneer of modern geology because he realized the features of the earth: mountains, sedimentary rocks could be explained by processes that we see operating today (i. e. principle of uniformitarianism) The earth is about 4. 5 billion years old. In 1913 arthur holmes published "the age of the earth" the first major effort to date the planet using radiometric dating. The age of the earth can be determined from age of meteorites, moon rocks, data from astronomy on age of solar system and universe etc. Numerical dating puts absolute values (e. g. millions of years) on the ages of rocks and geologic time periods: uses radioactive decay of unstable isotopes. Every atom of a given elements has the same # of protons (e. g. carbon has 6) but some atoms of that elements may have different neutrons (e. g. carbon 13 has 7 neutrons) and these are called isotopes.
