geology chapter 1
2 methods of dating rocks
absolute age and relative age
the asthenosphere
below the lithosphere. tectonic plates rest on the asthenosphere. easily deformed or partially molten part of the mantle
three great themes in Earth History
deep time, plate tectonics, evolution of life
relative age
determining sequence of rock formation without knowing the absolute age
3 plate boundries
divergent, convergent, transform
plate tectonics
explains many large scale patterns in earth's geological record. examples: earthquakes, volcanoes, mtn. ranges
what were darwin and wallace
first people gather convincing amount of evidence in support of evolution. also proposed a mechanism for evolution called natural selection
evidence for evolution by Darwin
fossils provide evidence for changes in life
Evolution of life
living things today are different than they were years ago because of changes in the environment and competition for food
2 major branches of geology
physical and historical
divergent
plates move apart from one another
convergent
plates move toward one another
transform
plates slide past one another
absolute age
quantifying the age of the rock/mineral. methods used to determine ages involve the decay rate of radioactive isotopes
steps to the scientific method
questions, hypothesis, theory, scientific law
deep time
recognition of the immensity of geologic time. this is geology's most important contribution to human knowledge
what are plate movements a result of?
result of the movement of heat from earth's core to the surface. typically only a few millimeters per year
geochronology
science that deals with the aging of rocks
where do you find a fossil
sedimentary
physical geology
study of Earth materials and processes
natural selection
survival of the fittest
what provided us the tools to find the absolute age of a rock
the discovery of radioactivity in 1896
the lithosphere
the rigid outer layer of Earth that includes the crust and uppermost part of the mantle. oceanic and continental crust
historical geology
the study of origin and changes of Earth and life through time
what is geology?
the study of the earth
Scientific Method
used to find answers to questions and solutions to problems
what the is scientific method used for
used to find answers to questions and solutions to problems
theory
when there is a large body of evidence or experimental or observational support it becomes this
when was earth formed
4.56 billion